Tag: IMS

OTT ( Over the Top ) Communication applications

Market trends are not in favour of Telecom Service /providers with increasing use of OTT ( Over The Top ) applications like WhatsApp, Facebook messenger, Google hangouts, skype, Viber, etc. OTT applications are often blamed to take a stake in voice traffic revenue by using IP calls where the telco could’ve charged based on its rate plan of call seconds. This especially intensifies for long-distance or international calls where customers can use OTT providers instead of expensive telco rate plans.

What is an OTT ?

An Over The Top ( OTT ) application is one which provides communication services over Internet . Therefore these bypass the communication billing system setup by a Telecom Operator , resulting in no gain or loss of revenue to Telecom Operator who is providing the Internet service to user in first place .

Hence we see that OTT are major source of concern for Telecom Operators whose traditional and obviously expensive ( when compared to OTTs free service ) billing models are facing disruption .

Telecom Regulatory bodies around the world

The telecom regulatory authorities in some of the countries are for example listed as :

  • Afghanistan Telecom Regulatory Authority (ATRA) – Afganistan
  • Australian Communications and Media Authority (ACMA) – Australia
  • Bangladesh Telecommunication Regulatory Commission (BTRC) – Bnagaladesh
  • Canadian Radio-television and Telecommunications Commission (CRTC) – Canada
  • Ministry of Information Industry (MII) – China
  • Autorité de Régulation des Communications Électroniques et des Postes (ARCEP) – France
  • Bundesnetzagentur (BNA) – Germany
  • Telecom Regulatory Authority of India (TRAI) – India
  • Ministry for Communications and Informatization of the Russian Federation (Minsvyaz) – Russia
  • Infocomm Development Authority of Singapore (IDA) – Singapore
  • Independent Communications Authority of South Africa (ICASA) – south Africa
  • Federal Communications Commission (FCC) , National Association of Regulatory Utility Commissioners (regulators of individual states) (NARUC) , CTIA – The Wireless Association (CTIA) – USA

Such telecom regulatory bodies get to decide whether to enforce differential price to end consumers for using OTT so that telecom service providers can benefit or keep the Internet fair and open by passing Net Neutrality Laws and Bills and amendments .

What is Net Neaurality ?

The fundamental principle of Net Neurality is that Telecom Operators should not block , slow down or charge consumers extra for using other services as their means of communication. This states that it is wrong to charge users above the regular data rates for using VOIP apps and other internet based communication services.

The following counteries have adopted principles of Net Neutrality by passing bills or making law .

  • Chile – Chile’s General Law of Telecommunications, “No [ISP] can block, interfere with, discriminate, hinder, nor restrict the right of any Internet user of using, send, receive, or offer any content, application, or legitimate service through the Internet, as well as any activity or legitimate use conducted through the Internet.”
  • Brazil – ” Internet Bill of Rights ” makes equal access to internet mandatory in Brazil .
  • Netherlands – Even European Union has adopted Netherlands’ Net Neutrality amendment which reads “traffic should be treated equally, without discrimination, restriction or interference, independent of the sender, receiver, type, content, device, service or application.”
  • USA – Citizens make ‘We the People’ platform to ‘Restore Net Neutrality By Directing the Federal Communications Commission (FCC) to Classify Internet Providers as ‘Common Carriers‘. Therefore not allowing them to either throttle speed by paid prioritization , discriminate in pricing or block any broadband access to legal content .  Above facts are from this tech.firstpost.com article.

 

Inspite of the fact that I Support Net Neutrality with all my heart , as a telecom engineer I understand the cost investment made by Telecom operators in providing am efficient communication network to its subscribers ( Access , Network and Application layers ). Therefor I do have my sympathies with the Telcos and to level out the wide ranging conflict between Telcos and  ISP ( Internet Service Providers ) , I pen down the following points which reflect the Telecom Operators Problems and also highlight the solutions that can be adopted to counteract the OTT threat .

Depleting revenue for Telco

  1. Messaging – OTT messaging cost operators $13.9 billion, or 9% of message revenue in 2013
  2. Voice – Voice services under threat from VOIP services like Skype, Viber
  3. OTT apps – Voice & Message apps have been the operator’s biggest headache. Its time Operator should launch its own OTT Services
  4. Data Traffic – The utilization is yet to reach its peak. Will face challenges from  WiFi access
  5. Critical Pain areas – Erosion of Operator’s revenue from voice and (especially) messaging

Telco’s OTT Application

At this stage, a telecom Service provider / Operator must enter the apps market and bring forth a Messenger which is more powerful, interactive and awesome than an OTT application. Fortunately, the Operator can always couple this application with his background telecom infrastructure to provide the edge in performance and functionalities.

Road block while developing a OTT application for a Telecom Service Provider :

  • Investment in Data Network is not being utilized due to lack of service
  • Reuse of Existing business Logic and extending the service reach across devices and networks is tough
  • Operator already has full fledged network Infrastructure in Place
  • Desire for minimum CAPEX while investing in new technologies
  • compete with OTT players and open new revenue streams is a challenge

Next we find the way of solving the problems and integrating them together to form a Solution .

OTT Application for Telecom Service provider

  • Introduce new services to benefit from investment on Data Plans and Bandwidth
  • Expose REST API to enable 3trd party Integration with existing network Infrastructure
  • Partner with individual OTT players to make new services  that do not compete on core competencies like billing etc
  • Use protocols like SIP that reduce CAPEX and have goto market more quickly
  • Go for enriched service that lead to better user experience

This write-up outlines the process of creating an OTT application for a Telecom Service Provider. Components for the application include cloud Address Book, Video Chatting, Location share, Contact synchronization ,REST-based thin client , OS and device agnostic etc shown in the figure below:

telco's OTT app
telco’s OTT app

The Application  is designed to close knit with Operator’s own infrastructure hence the crucial entities like Network Address Book , Location Service are synced and fetched from Backend Network .

OTT application Feature Overview

Smart Address Book

  • Automatic: Get contacts from Gmail, Facebook
  • Fast search by first, last name, frequently
  •   dialed number
  • Roadmap: View calendar events
  • Personal: Get image from Gmail and display in   contacts list

Geo Location

  • Share own location during chatting
  • Get map for calculating the distance between two chat users
  • Roadmap : Trigger device (say Switch on/off AC before reaching home) from a threshold distance away from home   location

Messaging

  • Ad-hoc Chat
  • Session Based Chat
  • Voice Input for texting
  • Presence information of contacts
  • RoadMap: Legacy message integration

Telephony

  • Voice call to mobile
  • Voice call to PSTN
  • Video call to other @imAll user
  • Share images during voice call to other

Device agnostic

  • Compatible with IOS, windows
  • Can run as native app on ipad
  • Can run as browser client on windows
  • RoadMap: native app for android, windows phone,blackberry10

Roadmap

features of Unified Communications ( UC)
features of Unified Communications ( UC)
  • To upgrade the application and provide enganced and enrich service support the I propose the following roadmap.
  • From plain vanilla voice and video calling ( supported by every other OTT application ) our application should progress towards  legacy telecom support whihc included PSTN , GSM , ISDN etc . This requires backbone of telecom network and a good setup for media codec conversion to suit various legacy media codecs .

Road Map  from Traditional to New age services 

  1. Voice and video calling
  2. Legacy services support like MMS and SMS
  3. Integration with 3rd party Vendors
  4. Give new enriched services like Multilingual support , file transfer , screen-sharing etc
  5. give facility to integrated web plugins for web calling

To keep the interest of customers it is essential that the application be supported on other popular OTT services like skype  , Gtalk . for exmaple a caller should be able to make call from Skype  / Gtalk to our application .Multilingual capabilities, support for larger protocol spectrum will just act like icing on the cake .

How does it benefit the Operator??

  1.  Saves on development cost and time
  2.  Device Agnostic OTT Applications
  3. Simplified Service deployment
  4. Saves licensing cost per client
  5. Reuses existing Messaging and   Address Book service logic.
  6. Open New Revenue Streams for operator
  7. No separate SIP stack required for the client
  8.  Faster Time to Market

Update : At the time of writing this post I did not anticipate the wave of change that bring focus on subjects like “net neutrality” , ” Save the internet” and “free internet”. However now most of the telcos providers have either joined the bandwagon by prividing SIP trunk endpoinst for cloud teelphony providers ( eg twilio, Google Calls) or have made their own IP call application for B2B customers.

Service Creation Environment (SCE ) for SIP Applications

I hoped of making a SIP application Development environment a year back and worked towards it earnestly . Sadly I wasn’t able to complete the job yet I have decided to share a few things about it here .

Aim :

Develop  a SCE ( Service Creation Environment ) to addresses all aspects of lifecycle of a Service, right from creation/development, orchestration, execution/delivery, Assurance and Migration/Upgrade of services.

Similar market products :

  • Open/cloud Rhino
  • Mobicents and Telestax

Limitations of open source/other market products:

  • Free versions of the Service Creation Environments do not offer High Availability.
  • High Cost of Deployment grade versions.

Solution Description

I propose a in-house Java based Service Creation Environment “SLC SCE”. The SLC SCE will enable creation of JAINSLEE based SIP  services. It can be used to develop and deploy carrier-grade applications that use SS7 and IMS based protocols such as INAP, CAP, Diameter and SIP as well as IT / Web protocols such as HTTP and XML.

Benefits:

  • Service Agility
  • Significantly Lower price points
  • Open Standards eliminate Legacy SCP Lock-in

Timeline

  • Java-based service creation environment (SCE) – 1.5 Months
  • Graphical User Interface (GUI) and schematic representations to help in the design, maintenance and support of applications – 1.5 months
  • SIP Resource Adapter – 1 month

Architecture

Service Creation Environment (SCE) for SIP Applications
Service Creation Environment (SCE) for SIP Applications

In essence it encompasses the idea of developing the following

  1. SIP stack
  2. Javascript API’s
  3. Java Libraries for calling SIP stack
  4. Eclipse plugin to work with the SIP application development process
  5. Visual Interface to view the logic of application and possible errors / flaws
  6. SDKs (  Service Development Kit) , which are development Environment themselves

Extra Effort required to put in to make the venture successful

  1. Demo applications for basic SIP logic like Call screening , call rerouting .
  2. tutorial to create , deploy and run application from scratch . Aimed at all sections ie web developer , telecom engineer , full stack developer etc .
  3. Some opensource implementation on public repositories like Github , Google code , SourceForge
  4. Perform active problem solving on Stackoverflow , CodeRanch , Google groups and  other forums .

—————————————————————

Harmonization of services between generations of telecommunication core layers

A communication system can be made up of many components which are individually undergoing evolution such as access layer generations, and core layer upgrades. Harmonized and uniform open standard-based service delivery platforms over legacy Proprietary codebase is the preferred choice for most service providers to save the investment in their infrastructure and programming while keeping up with the shift in technology. I shall be editing this post to discuss more on the process of Service Harmonization.This saves the Telecom Service Provider the trouble of rewriting call logic with every telecom generation evolution ie IN to SIP to Web based WebRTC phones.

Landscape shift for Telecommunication Service providers includes Transmission layer which is ATM/Frame relays moving towards IP/MPLS. Access Layer hardware specific to POTS / PSTN / ISDN upgrading towards NGN and VOIP.  Packet Switched Next gen Soft Switches based on SIP.

Telecommunication service Harmonization

The Service Harmonization Layer does the job of holding all new and legacy services while providing uniform interface to interact with access network regardless of the back-end Call program logic. It involves consolidation for the service layers across IMS and legacy mobile network and Orchestration to extend the capability of underlying platform to support multiple IN variants. Diagrammatic depiction of scope of Service Harmonization.

Gateways based Harmonization

Service Broker based Harmonization

As CSPs evolve their networks for LTE, the resulting networks present tremendous challenges in voice services and application delivery. Realizing this opportunity, the telecom software industry has come forward with a purpose-built network element: the Service Broker, a solution specifically designed to overcome network architecture challenges and ensure voice service delivery from any network domain to any other network domain. Service Brokers are placed between the application layer and the control layer.

A service broker is a service abstraction layer between the network and application layer in a telecom environment. SB( Service Broker ) enables us to make use of existing applications and services from Intelligent Network’s SCP ( Service Control Point ), IMS’s Application Server as well as other sources in a harmonized manner

Legacy switches vs Softswitches

Legacy switches are circuit-switched, monolithic, propertiary and expensive while Softswitch is packet-switched and open interfaced. They are scalable and vendor-independent which enables easy convergence. Softswitches forms the basis for a service harmonization engine as they increase the granularity and power processing distribution of the Network

Service Delivery Layer in Legacy vs Harmonized Services

Legacy Service Layer has a function-centric architecture having multiple domain-specific session types such as Mobile calls, IPTV and broadband. Harmonized service delivery layer has Open APIs and is essentially Data-centric. This leads to fast and agile development and deployment of convergent services specifically IMS system providing the framework for underline network agnosticism across fixed and mobile.

Service Broker 1
Service Broker 2
Service Broker Architecture for IN and IMS
Service Creation Environment (SCE ) for SIP Applications

SIP Presence

We have already learned about Sip user agent and sip network server. SIP clients initiates a call and SIP server routes the call . Registrar is responsible for name resolution and user location. Sip proxy receives calls and send it to its destination or next hop.

Presence is user’s reachability and willingness to communicate its current status information . User subscribe to an event and receive notification . The components in presence are :

Presence user agentpresence components
Presence agent
Presence server
Watcher

Image source  : http://msdn.microsoft.com/en-us/library/bb896003.aspx

Sip was initially introduced as a signaling protocol but there were Lack of method to emulate constant communication and update status between entity
Three more method was introduced namely – Publish , Subscribe and Notify

Subscribe request should be send by watchers to presence server
Presence agent should authenticate and send acknowledgement
State changes should be notified to subscriber
Agents should be able to allow or terminate subscription

presence flow

Image source http://download.oracle.com/docs/cd/B32110_01/ocms.1013/b31497/about_sdp.htm#BABDHHCJ

Traces of various SIP requetss and response in presence are are follows :

subscribe request

SUBSCRIBE sip:presentity@example.com SIP/2.0
      Via: SIP/2.0/UDP host.example.com;branch=z9hG4bKnashds7
      To: <sip:presentity@example.com>
      From: <sip:watcher@example.com>;tag=12341234
      Call-ID: 12345678@host.example.com
      CSeq: 1 SUBSCRIBE
      Max-Forwards: 70
      Expires: 3600
      Event: presence
      Contact: sip:user@host.example.com
      Content-Length: 0
 

200 OK to subscribe request

SIP/2.0 200 OK
      Via: SIP/2.0/UDP host.example.com;branch=z9hG4bKnashds7
       ;received=192.0.2.1
      To: <sip:presentity@example.com>;tag=abcd1234
      From: <sip:watcher@example.com>;tag=12341234
      Call-ID: 12345678@host.example.com
      CSeq: 1 SUBSCRIBE
      Contact: sip:pa.example.com
      Expires: 3600
      Content-Length: 0
 

Notify Request

NOTIFY sip:user@host.example.com SIP/2.0
      Via: SIP/2.0/UDP pa.example.com;branch=z9hG4bK8sdf2
      To: <sip:watcher@example.com>;tag=12341234
      From: <sip:presentity@example.com>;tag=abcd1234
      Call-ID: 12345678@host.example.com
      CSeq: 1 NOTIFY
      Max-Forwards: 70
      Event: presence
      Subscription-State: active; expires=3599
      Contact: sip:pa.example.com
      Content-Type: application/pidf+xml
      Content-Length: …
 

200 OK success response to notify

SIP/2.0 200 OK
      Via: SIP/2.0/UDP pa.example.com;branch=z9hG4bK8sdf2
       ;received=192.0.2.2
      To: <sip:watcher@example.com>;tag=12341234
      From: <sip:presentity@example.com>;tag=abcd1234
      Call-ID: 12345678@host.example.com
      CSeq: 1 NOTIFY
 

PUBLISH Request

PUBLISH sip:presentity@example.com SIP/2.0
Via: SIP/2.0/UDP pua.example.com;branch=z9hG4bK652hsge
To: <sip:presentity@example.com>
From: <sip:presentity@example.com>;tag=1234wxyz
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
Max-Forwards: 70
Expires: 3600
Event: presence
Content-Type: application/pidf+xml
Content-Length: …

200 OK success response to PUBLISH

SIP/2.0 200 OK
Via: SIP/2.0/UDP pua.example.com;branch=z9hG4bK652hsge
;received=192.0.2.3
To: <sip:presentity@example.com>;tag=1a2b3c4d
From: <sip:presentity@example.com>;tag=1234wxyz
Call-ID: 81818181@pua.example.com
CSeq: 1 PUBLISH
SIP-ETag: dx200xyz
Expires: 1800

A call flow depicting presence in action is as given below :

presence subscribe notify

Image source http://www.cisco.com/en/US/i/100001-200000/190001-200000/190001-191000/190463.jpg

security considerations for Presence service include:

  • Access control.
  • Notifier privacy mechanism.
  • Denial of service attacks.
  • Replay Attacks.
  • Man-in-the-middle attacks.
  • Confidentiality.

some solutions for security implementation are

  • Sip registration
    TLS
    Digest Authentication
    S/MIME

References :

Rfc 3856 http://www.ietf.org/rfc/rfc3856.txt
Rfc 3265 http://www.ietf.org/rfc/rfc3265.txt
Rfc 2778 http://www.ietf.org/rfc/rfc2778.txt
Rfc 3261 http://www.ietf.org/rfc/rfc3261.txt
Rfc 3903 http://www.ietf.org/rfc/rfc3903.txt
http://en.wikipedia.org/wiki/Session_Initiation_Protocol

Summary :

Presence is a way to have sustained stateful communication. The SIP User agents can use presence service to know about others user’s online status . Presnece deployment must confirm to security standards .

Legacy Telecom Networks

I use the term legacy telecom system many a times , but have not really described what a legacy system actually is . In my conferences too I am asked to just exactly define a legacy system . Often my clients are surprised to hear what they have in current operation is actually fitted in our own version of definition of ” Legacy system “. This write up is an attempt to describe the legacy landscape . It also describes its characteristics, elements and transformation.

Source : Unknonw. Figure describes an IP based communication system catering to various endpoints and networks

Characteristics of Legacy Systems

1. Analog Signals

1G , introduced in 1980s , used analog signals as compared to digital in 2G onward. In 1G voice was modulated to higher frequency and then converted to digital while communication with radio towers .

2.Legacy system have ATM / Frame Relay transmission .

This is basically Hardware Specific and results in High Expenses.

3. Legacy systems have POTS / PSTN / ISDN as their access layer technology .

Access layer is the first layer of telecom architecture which is responsible for interacting directly with the end use / subscriber . Legacy system technologies are again Hardware  Specific , bear High Expenses and offer Low stability.

Physical transmission media include :

  • Twisted wire (modems)
  • Coaxial cable
  • Fiber optics and optical networks – Dense wavelength division multiplexing (DWDM)

4. Legacy system use Traditional Switches / ISDN in their Core Layer

Core layer is the main control hub of the entire telecom architecture . Using old fashioned switches render high CAPEX ( capital Expenditure ) and OPEX ( Operational Expenses ) .

5. In the service delivery front legacy system employ Traditional IN switches

These are very Hardware Centric.

PSTN (Public Switched Network)

MAN (Metropolitan area networks) connected ~30 miles of LAN (local networks) with a BN (backbone network). WAN(Wide Area Network) connected these MANs for longer distances ~100 miles. The telco were carriers with these larger internetworks and connections such as At&T or BellSouth. This led to development of PSTN.

PSTN were Circuit – Switching telephone network which were designed to carry analog data. Connnecting over PSTN required a modem convertor which converted analog to digital at 28/56 Kbps. During the set up portion of a telephone call, a special circuit is created, which is then torn down when the call is completed.

TDM (Time Division Multiplexing)

TDM was designed to provide continuous, compact and orderly data transfer for voice and video. It does so using a constant bandwidth over a secure connection.

ISDN (Integrated Service Digital Network)

ISDN can provide end-to-end digital communications for Fax, Data, audio, image and video transmission. It is a switched digital telecommunication line that can be delivered over regular copper wires.
Speed for a single ISDN line is 128 Kbps. Multiple ISDN lines can be combined together to achieve higher communication speeds. It was mostly used to provide remote access to LANs.

Digital lines with ISDN

  • Basic Rate Interface or BRI are used for home or SOHO connection
    • 2B + D channel
  • Primary Rate Interface or PRI is used for large businesses
    • 23 B channels and 1 D channel

B channels are known as bearer channels and is used to carry information
D channel is known as the Delta channel used for signalling purposes

Services of Legacy Telecom Networks

a) Virtual Private Network (VPN)

An Intelligent Network (IN) service, which offers the functions of a private telephone network. The basic idea behind this service is that business customers are offered the benefits of a (physical) private network, but spared from owning and maintaining it

b) Access Screening(ASC)

 An IN service, which gives the operators the possibility to screen (allow/barring) the incoming traffic and decide the call routing, especially when the subscribers choose an alternate route/carrier/access network (also called Equal Access) for long distance calls on a call by call basis or pre-selected.

c) Number Portability(NP)

An IN service allows subscribers to retain their subscriber number while changing their service provider, location, equipment or type of subscribed telephony service. Both geographic numbers and non-geographic numbers are supported by the NP service.

Also Read

Evolution of voice Communication
Telecommunications convergence – VoIP, PBX and IMS

SIP/VOIP transformation towards IMS (Total IP)

The telecommunications industry has been going through a significant transformation over the past few years. At the outset incumbent operators used to focus on mainly basic voice services and still remained profitable due to the limited number of players in the space and requirement of huge amounts as initial investment.

However, with the advent of competitive vendors, rise in consumer base, and introduction of cost effective IP based technologies a major revolution has come about. This has enabled operators to come out of their traditional business models to maintain and enhance subscriber base by providing better and cheaper voice, multimedia and data services in order to grab the biggest possible share in this multi- billion dollar industry.

The evolution in Telecom industry has been accelerating all the time. The Next-Generation Operators wants to keep pace with the rapidly changing technology by, adapting to market needs and looking at the system and business process from multiple perspectives concurrently. Communication Service Providers (CSPs) need to consider several factors in mind before proposing any solution. They need to deploy solutions which are highly automated, highly flexible, caters to customer needs coupled with ultra low operating costs.

Upgrading a softswitrch solutions to IMS

The Softswitch is decomposed into two logical components of a subscriber-facing unit and a PSTN-facing unit. 

  • Subscriber facing unit in Softswitch is upgraded to AGCF (Access Gateway Control Function) 
  • PSTN facing unit is upgraded to MGCF (Media Gateway Controller Function) to interwork with IMS as shown.

By separating the Softswitch into these components, the network can be more easily scaled for better overall network efficiencies. More AGCFs can be added as required, allowing the network to scale with an increase in subscribers. Similarly, More PSTN trunks can be added as traffic increases. Once PSTN and subscriber control functions are separated, the IMS elements, CSCF and BGCF functions can be introduced. BGCF is the interface for interconnecting IMS with legacy PSTN networks.

New SIP-based services can now be rapidly rolled out by deploying new Application Servers (AS) and its integrations to other SBC for UCC( unified communication and colloboartion ) systems. IMS has 3GPP specified ISC interface, which is a SIP-based interface for interfacing-to-application servers. Using these constructs, multiple application servers from multiple vendors can be interconnected over the IMS ISC interface.

Intelligent Networks( IN)

Telecom networks (2014) are made up of integrated service digital network (ISDN), the public switched telephone network (PSTN) ,the Public Land Mobility Network (PLMN) and many others. Intelligent networks (IN) ensures that call control is handed over to a control platform. The control platform determines how the establishment of this call shall continue. Applying IN to any of these networks has in common that call establishment is intercepted at a designated node in the network

By hosting new services on the new platform and combining new and old services CSP‟s aim to provide service bundles that would generate new revenue streams. This process is largely dependant on IMS ( IP Multimedia Subsystem ) architecture .

Transformation towards IMS (Total IP)
Transformation towards IMS (Total IP)

Optimization in operator landscape evolve as result of synergistic technologies that come together to address the innovation and cost optimization needs of operator for better user experience. In following sections different technological evolutions that are affecting overall operator ecosystems have been discussed with focus towards Service Layer.

Fixed/mobile convergence(FMC) with IMS

“Fixed Mobile Convergence is a transition point in the telecommunications industry that will finally remove the distinctions between fixed and mobile networks, providing a superior experience to customers by creating seamless services using a combination of fixed broadband and local access wireless technologies to meet their needs in homes, offices, other buildings and on the go.”

 Fixed-Mobile Convergence Alliance (FMCA)  2004

System can communicate over the cellular network, or act as a new endpoint on the IP network. Home Subscriber Server (HSS) manages subscriber data uniformly between the cellular and IP worlds. The Handoff Server runs on top of the ISC interface, and provides a seamless experience when subscribers move from the cellular network to a Wi-Fi network. The AGCF remains the functional centre of the network, but with the introduction of the HSS, has added the Cx and Sh interfaces defined by the IMS.

Legacy to IP transformation

This section broadly covered the aspects of migration from legacy IN solution to new age JAINSLEE framework based one. Applies to Legacy IN hosting voice based services mostly  such as VPN, Access Screening ,Number Portability, SIP-Trunking,Call Gapping.

Most operator environments have seen a rise in the number of service delivery platforms. Also complexity of telecom networks have increased manifold hence CSPs are facing multiple challenges. Increased efforts and costs are required for maintaining all the SDP platforms. These platforms are generally of different vendors and cater to different technologies thereby greatly increase chances of limiting the scalability and flexibility of the operator landscape. More effort required for sustaining the life cycle of the platform and challenges in integrating non compatible SDPs due to proprietary design have been stumbling blocks in the progress of CSPs across the world.

To overcome these challenges there is trend in the market to move towards SDP consolidation wherein instead of maintaining several SDPs with their proprietary design CSPs prefer maintaining a single or less number of SDPs having standardized interfaces.

SDP consolidation
SDP consolidation (1)
SDP consolidation (2)

As illustrated in the above figure there is a transition that is taking place in the industry towards consolidation of service delivery session control. This would provide a cost effective sustenance of existing applications and the rapid creation and deployment of new services leading to increased revenue recognition by CSPs.

  • Agile Development
  • Innovative services
  • open SOA based architectures
  • IN/NGN Platform and Services
  • Reuse of existing investments in legacy service platforms
  • low cost of new service development
  • faster time to market
  • Monetize investment in Network Infrastructure uplift – SIP trunking, VoLTE etc.

Services that should be covered  in the Scope of Migration from fixed line to IP telephony are:

  • Virtual Private Network (VPN) : An Intelligent Network (IN) service, which offers the functions of a private telephone network. The basic idea behind this service is that business customers are offered the benefits of a (physical) private network, but spared from owning and maintaining it.
  • Access Screening(ASC): An IN service, which gives the operators the possibility to screen (allow/barring) the incoming traffic and decide the call routing, especially when the subscribers choose an alternate route/carrier/access network (also called Equal Access) for long distance calls on a call by call basis or pre-selected.
  • Number Portability(NP) : An IN service allows subscribers to retain their subscriber number while changing their service provider, location, equipment or type of subscribed telephony service. Both geographic numbers and non-geographic numbers are supported by the NP service.

 

WebRTC based Unified Communication platform

Using WebRTC Solution for Delivering In Context Voice which provides new monetizing benefits to the Enterprise customers of Service Providers. This includes following components:

  • WebRTC Gateway for implementation for inter-connect with SIP Legacy
  • Enhancement of WebRTC Client with new features like Cloud Address Book, Conferencing & Social Networking hooks.
  • Cloud based solutions
INtoJAISNLEE

Challenges in Migration to IMS  (Total IP )

Since long I have been advocating the benefits of migration to IMS  from a current fixed line / legacy/ proprietary VOIP / SS7 based system . However I decided to write this post on the challenges in migration to IMS system from a telecom provider’s view.  Though I could think of many , I have jot down the major 4 . they are as follows :

Data Migration challenges

  • Establishing a common data model definition
  • Data migration seamlessly
  • Configuration management
  • Extracting data from multiple sources and vendors , that includes legacy systems
  • Extracting data due to its large scale and volume

Training

  • Creating an effective knowledge share and transfer for live operations
  • Training in fallback plans, standards and policies .

Customer impact

  • Minimized customer outage
  • Enhance customer experience by delivering quality services on schedule
  • Ensuring security of customer’s confidential data
  • Transfer of customer services without any impact.

Testing in replicated environment

  • Physical pre-transfer test
  • Reducing cycle time
  • Verification and validation at every change in data environment
  • Detect production issues early in the test -lifecycle

Fallback plans

  • Pilot program and real network simulation for ensuring preparedness
  • Tracking changes in new network

 

IP Multimedia Subsystem (IMS)
IP Multimedia Subsystem (IMS) – detailed part2
Service Broker Architecture for IN and IMS
5G and IMS

Internet Telephony Convergence- JAINSLEE Platform

Convergence : Telephone networks and computer networks converging into single digital network using Internet standards.

Components in a Network

  • Client computer
  • Server computer
  • Network interfaces (NICs)
  • Connection medium
  • Network operating system
  • Hub or switch
  • Routers- Device used to route packets of data through different networks, ensuring that data sent gets to the correct address

1

Figure :simple computer network, consisting of computers, a network operating system residing on a dedicated server computer, cable (wiring) connecting the devices, network interface cards (NICs), switches, and a router.

2

Figure of a Enterprise Network : local area networks (LANs) linked to enterprise level / corporate network . It consists of :

  • Powerful servers
  • Web site
  • Corporate intranet, extranet
  • Backend systems
  • Mobile wireless LANs (Wi-Fi networks)
  • Videoconferencing system
  • Telephone network
  • Wireless cell phones etc

The convergence of Internet and Telephony opens up new revenue streams for the Communication Service Providers by delivering new innovation based convergent applications.

Before discussing digitization of Communication and telecom we need to first understand packet switching .

What is Packet switching ?
It is a method of slicing digital messages into packets, sending them along different communication paths as they become available. Then reassembling these received packets at destination. It is a more efficient use of network’s communications capacity.
Previous circuit-switched networks required assembly of complete point-to-point circuit.

What triggered this Technology development?

The Internet, IPTV and Social Media networking is evolving dynamically in the end user space of Communication Service Provider. This opens door for delivering new innovative services to end user through these converged applications.

A SP( Service provider ) has to work with multiple Communication Providers globally and based on the experience with the customers, has to conceptualize and implemented new innovative use cases on open platform to reduce the cost and  migrate from legacy to Next Generation Networks.

What does convergence mean to

  • Equipment Vendors / EV
    • Femto / FMC
    • Challenges in System Integration
    • Box to Solution Sales
    • Services software based
  • Enterprises
    • Low Capex – Hosted Models
    • Enterprise Mobility
    • IP Enabled Services
    • UC to UC
    • Web Integration with Mobility
  • Telco
    • Enterprise communication will be a big focus Area
    • Push to EVs for CAPEX
    • Wish to leverage Legacy as well
    • Challenges in Vertical Solutions
    • Will face challenges by OTT players

 

What will it do, how and in which situation ?

The underlying technology of Internet Telephony Convergent Platform is JAIN SLEE Framework which is open standard for developing core network based applications. It enables development of network agnostic applications , implemented through resource adapters for deploying same applications over different networks like SIP/IN etc.

JAINSLEE framework provides capability to form new complex services through reusable service building block in much easier way then traditional methods. This reduces cost for launching new services and bundled different services into the new convergent service in network agnostic way. 

It also bring benefits in term of reducing the dependency on Vendor proprietary platform and eventually bringing down cost involved and Time to market in launching new service.

The OpenCloud Service Layer OpenCloud

picture courtesy : Opencloud.com

What problem does this technology seek to solve?

Today communication service provider are facing vendor locking situation where most of services deployed are platform dependent which requires huge cost of investment for launching new services. Traditional service development platforms are major roadblock for operators to launch new collaborative services which involves both voice and data channels as they are not based on open standards and are tied to the vendor specific technologies. Also in a fast changing technology the operators need to switch their focus on new innovative services through which operator can monetize services and provide the value added experience to their end customers. To enable it we proposed and implemented framework which not only act as the new Internet Telephony convergent platform but also in sync with their future network transformation strategy as it is based on open standards. Through this platform same applications can be targeted to different segment of users with minimal cost impact. Some of the application which we have developed are detailed below.

a) Parental Control is an application through which parents can have control over their children’s Internet video on demand request. Once a child requests for any video, preview of the same(short clip of video) at the same instance is send to parents’ smart phones. Parents can see preview and can decide there and then weather it is adequate for his/her kids or not, and can either allow or deny through his mobile.

b) IPTV/VOD session mobility is a service which allow user to transfer their ongoing voice call/video-on-demand session from their smartphone to desktop/computing device/smart-device and vice-versa seamlessly.

c) Converged application like unified communication platform for trader community take advantage of both voice and data services and help trader community in terms of analytics and decision making process.

What is the specific breakthrough of this technology?

Internet and Telephony are two major drivers in Telecom domain. Hence the concept of convergence of Internet and Telephony is of great interest for the Telcos. Internet telephony, also known as voice-over-IP or IP telephony is the real-time delivery of voice between two or more parties, across networks using the Internet protocols, and the exchange of information required to control this delivery. New innovative use case scenarios  have been conceptualized and implemented considering new user behavior changes. These bring in value addition to CSPs in order to bring more revenue streams. Solutions like Secure VOIP bring another dimension of innovation as it provides a secured voice communication over the internet using open source software like Asterisk. This solution helps business reduce their operational communication costs using encrypted standard security algorithms.

Asterisk- Applications (1)

pic courtesy : asterisk.com

How does this technology compare with other technologies? 

Internet telephony convergent platform has the unique value proposition based on new innovative use case scenarios using multiple underlying technologies. These scenarios are implemented using Open Standards. Though many other vendors’ platform also provides some of the facilities of platform in part and pieces but none of them give complete end to end solutions suits to operators as our Internet Telephony convergent platform provides.

How does it help in achieving the goals?

We consider it as solution which can act as foundation block to build a long term partnership with operators especially in area of services landscape. This solution enables operator to monetize different voice and data convergent services and in sync with the operator’s next generation transformation initiative. The services acts as catalyst to increase the data usage of end-users. Strong business case can be built with these services by operators as they meet the future demands of tech savvy end users. These services not only fill the void between communication service provider and social media/internet/video-on-internet but also take advantage of reach of social media/internet and eventually enable operator to add new revenue stream. These services can also help operator to increase their brand visibility with added advantage of social media and internet application bundled with their core services. Operator can charge it on per application basis or can be just carrier and charge for data usage. Convergent services which involves both the voice and data, enable operator to charge on voice services , data services and application usage. With our rich experience in convergent platform domain we believe we can convert significant opportunities in this space.

Explain your journey of Technology development ?

After seeding of concept of Internet Telephony convergent platform SP should explore partner product Software centric platforms like Open cloud, Oracle, Mobicient etc which offers the capability to deliver convergent applications at a low cost and using the open standards. Standards like JAIN SLEE provide capability for developing and delivering such applications across different type of underlying network. 

Mobicents Platform

pic courtesy : Mobicents.com

One can develop the complete solution using such open, standard platforms as a base . The complete solution takes care of the real-network issues and solutions for the same. There were many hurdles and roadblock at first. Adaptation to open standards like JAIN SLEE requires fast ramp up as it is quite complex technology. In a small stipulated time a core team should have developed competency through Partner Training inputs and Brain Storming sessions. To test framework at lab, there would be dependency on many open source software and strategic partner products. There would be many incompatibility issues. Its important that such issues be  sorted out by exhaustive explorations of products and by bug fixes .

Benefits expected if this Technology is implemented / commercialized 

a) Communication service providers are able to realize appreciable cost saving through Internet Telephony convergent platform Operators deployed in their network. This is so legacy platform were costly and difficult to manage. This platform brings innovative and cost effective way of launching new collaborative services which brings new revenue stream.

b) Improved Time to market

c) Extensible architecture for the service helps in extending the service for multiple markets.

Social Benefits

Unified communications, where voice, video, email, text and other messaging technologies are combined to provide greater flexibility for users by enabling new ways to transfer information and manage connectivity. Integration of collaborative services with the social media platform like Facebook , Linkedin , Twitter etc, increases the connectivity and value experience of end users. Through social media based convergent applications operator can further increase their reach to end users by utilizing underlying the Internet Telephony convergent platform.

My Insights 

Based on my personal experience while implementing this technology/platform, I think this solution act as catalyst for enabling the transition from network eccentricity to customer eccentricity. This movement is further supplemented through the reduced dependence on legacy vendors and increased adoption of open standard based platforms. Through the converged application layer for Telcos I envisage a platform which is agnostic to underlying network layer. Unified platform allows carriers, mobile operators, and cable operators to rapidly create, manage, and deliver converged video, voice, and data service bundles across multiple networks and devices. It enhance end user experience and enable Telcos to add new revenue stream by offering value added services to their customer. 

IMSSF and RIMSSF

This post particularly describes the gateways in IMS which communication back and forth with a legacy endpoints.To get a overview of IMS itself click here  and to get a detailed description of IMS and its architecture click here .

What is IM-SSF  ?

IP Multimedia Service Switching Function is a  gateway to provide IN service such s legacy VPN ( Virtual Private Network ).

IMSSFaltanai
IMSSF

 

What is R-IM-SSF  ?

Reverse IP Multimedia Service Switching Function Works on reverse principle to connect IN network  to IMS services using IMS services such as FMFM ( find me follow me ) .

RIMSSFaltanai

More link on telecom transformation , migration and inter-opereability :

Transformation towards IMS 

 

IP Multimedia Subsystem (IMS)

  • Why IMS ?
  • What benefits does IMS bring ?
  • Features of IMS Network
  • IMS Layers
    1. Transport / Media Endpoint Layer
      • Backhaul network
      • Border Gateways
    2. Session & Control Layer
      • HSS (Home Subscriber Server)
      • SCF (Call Session Control Function)
      • MGw (Media Gateway Control Function)
    3. Application Services Layer
      • TAS (Telephony Application Server)
      • IM-SSF ( IP Multimedia Services Switching Function)
      • OSA-GW (Open Service Access Gateway)
  • IMS-architecture
    • IMS standalone architecture
    • Interoperable IMS core for heterogeneous access networks

IMS is a an architectural framework for IP based multimedia rich communications. It was standardized by a group called 3GPP formed in 1999. It started as an enabler for 3rd generation mobile networks in European market and later spread to wirelne networks too. IMS became the key to Fixed Mobile Convergence (FMC).

Based on IETF Protocols (such as SIP, RTP, RTSP, COPS, DIAMETER, etc), IMS is now crucial for controlling conmmunication in a IP based Next Genration Network (NGN).

Communication service providers and telecom operators are migrating from circuit-switched networks to IMS technology with the increasing bandwidth (5G) and user expectations.

Why IMS ?

Early days TDM networks were not robust enough to support emerging technologies and data networking. There was a need to migrate from voic eonly network to Triple play network ( voice , video and data ). Other factors included :

  • rapid service development
  • service availiability in both home and roaming network
  • wireline and wireless convergence

Due to these above mentioned reasons TDM was outdated and IMS gained support .

What benefits does IMS bring ?

It offers counteless applications around rich multimedia services on wireless , packet swtched and even tradional circuit switched networks.

Easier to Create and Deploy New Applications and Services

  • (+)Enhanced applications are easier to develop due to open APIs and common network services.
  • (+) Third-party developers can offer their own applications and use common network services, sharing profits with minimal risk
    New services involving concurrent sessions of multimedia (voice, video, and data) during the same call are now possible.
  • (+) Reduced time-to-market for new services is possible because service providers are not tied to the timescales and functions of their primary NEPs

Capture New Subscribers,Retain Current Subscribers

  • (+) Better voice quality for business applications, such as conferencing, is possible
  • (+) Wireless applications (like SMS, and so on) can be offered to wire line or broadband subscribers.
  • (+) Service providers can more easily offer bundled services.

Lower Operating and Capital Costs

  • (+) Cost-effective implementation of services across multiple transports, such as Push-To-Talk (PTT), presence and Location-Based Services (LBS), Fixed-Mobile Convergence (FMC), mobile video services, and so on.
  • (+) Common provisioning, management and billing systems are supported for all networks.
  • (+) Significantly lower transport costs result when moving from time-switched to packet-switched channels.
  • (+) Service providers can take advantage of competitive offerings from multiple NEPs for most network elements.
  • (+) Reduced expenses for delivering licensed content to subscribers of different types of devices, encodings, or networks.

The strongest argument for adoption of IMS is that it follows established standards and open interfaces from 3GPP and ETSI. This makes it suited for interoperability, policy control accross networks, streamlined OSS/BSS, Value Added Services etc.

ims

Features of IMS network

  1. Abstraction from Underlying Network : IMS is essentially leading towards an open and standardized network and interface,irrespective of underlay network.
  1. Fixed /Mobile Convergence : Inter operability with Circuit Switched (CS) Mobile application Part (MAP)
  1. Roaming : Location awareness between home and visiting network.
  1. Application layer Call Control : IMS application layer has the provision for defining proxy or B2BUA based call flow completion . This leads to operator being able to introduce business logic into call sessions.

IMS is supplemented by SIP (IETF), Diameter (IETF) and H248(ITU-T).The release cycle of IMS is as follows

  • 2002-03-14 Rel-5  : IMS was introduced with SIP. Qos voice over MGW.
  • 2004-12-16 Rel-6 : Services like emergency , voice call continuity , IPCAN ( IP connectivity Access Network )
  • 2005-09-28 Rel-7 : Single Radio Voice Call Continuity , multimedia telephony,eCall ,ICS
  • 2008-12-11 Rel-8 : IMS centralized services , supplementary services and internetworking between  IMS and  Circuit Switched Networks,charging , QoS
  • 2009-12-10 Rel-9 : IMS emergency numbers on GPRS , EPS(Enhanced packet system) , Custom alert tone , MM broadcast/Multicast
  • 2011-3-23 Rel-10 : home NodeB, M2M, Roaming and Inter UE transfer
  • 2012-09-12 Rel-11 :-tbd
  • 2014-09-17 Rel-12 :- tbd
  • 2015-12-11 Rel-13 :- tbd

IMS Layers

Majorly IMS is divided into 3 horizontal layers given below :

2014-05-24_0015

Transport / Media Endpoint Layer

Unifies transports and media from analog, digital, or broadband formats to Real-time Transport Protocol (RTP) and SIP protocols. This is accomplished by media gateways and signaling gateways.

It also includes media servers with media processing elements to allow for announcements, in-band signaling, and conferencing. These media servers are shared across all applications (voicemail, interactive response systems, push-to-talk, and so on), maximizing statistical use of the equipment and creating a common base of media services without “hard-coding” these services into the applications.

Session & Control Layer

This layer arranges logical connections between various other network elements. It provides registration of end-points, routing of SIP messages, and overall coordination of media and signaling resources.

IMS core which is part of this layer primarily contains 2 important elements Call Session Control Function (CSCF) and Home Subscriber Server (HSS) database. These are explained below 

HSS ( Home Subscriber Server)

It is a database of user profiles and location information . It is responsible for name/address resolution and also authorization/authentication .

CSCF ( Call Session Control Function)

Handles most routing, session and security related operation for SIP messages . It is further divided into 3 parts :

  • Proxy CSCF: P_CSCF is the first point of contact from any SIP UA. It proxies UE requests to subsystem.
  • Serving CSCF: S-CSCF is a powerful part of IMS Core as it decides how UE request will be forwarded to the application servers.
  • Interrogating CSCF: I-CSCF initiates the assignment of a user to an S-CSCF (by querying the HSS) during registration.

Application Services Layer

The Application Services Layer contains multiple Application Servers (AS), such as:

  • Telephony Application Server (TAS) – for defining custom call flow logic
  • IP Multimedia Services Switching Function (IM-SSF)
  • Open Service Access Gateway (OSA-GW), and so on.

IMS Architecture

The IMS standalone architecture is suited for an all IP network

The IMS standalone archietcture is suited for an all IP network

Interoperable IMS core for heterogeneous access networks

Interoperable IMS core for heterogeneous access networks

References

  • IMS service Switching function and reverse service Switching function read here.
IMSSF and RIMSSF
IP Multimedia Subsystem (IMS) – detailed part2
Internet Telephony Convergence- JAINSLEE Platform
IMS in EPC ( Evolved Packet Core )

Update on IMS :

IMS has been mandated as the control architecture for Voice over LTE (VoLTE) networks. Also IMS is being widely adopted to mange traffic for Voice over WiFi (VoWiFi) systems.

IMS in EPC ( Evolved Packet Core )

Packet Switched and/or Circuit swicthed Communication

The earlier models were distributed between legacy circuit switched networks and evolving packet switched networks

Sources : NEC eNB SGW E-UTRAN PDG MME

With the massive improvents in quality of network srevices packet switched comunication protocls became more resilent and replaced the circuit swicthed protcols for realtime communication.

LTE ( Long Term Evolution )

LTE evolved its precursor Universal Mobile Telecommunication System (UMTS), which in turn evolved from the Global System for Mobile Communications (GSM).

It defines the access layer of Telecom architecture. EPC is the core of LTE system . LTE is often linked with evolved UMTS terrestrial radio access (E-UTRA) and evolved UMTS terrestrial radio access network (E-UTRAN). With this eco-system Evolved NodeB (eNodeB) is the base station for LTE radio.

Read more on Long Term Evolution (LTE), VOLTE and VOWifi 

What is EPC (Evolved Packet Core )  ?

EPC is a core network architecture framework by 3GPP. It conncets the E-UTRAN to server-PDNs and is largely responsible in controlling the application flow.

 Primarily EPC has 4 sub parts

  1. HSS
  2. Serving Gateway ( S-Gw)
  3. PDN gateway ( P-Gw)
  4. MME (Mobility Management Entity)

It is most often an IMS environment contgainings CSCF as Gateways with various roles .

IP Multimedia SubSystem was originally meant for evolved UMTS network to provider IP communication to mobile UAs. Today IMS is gaining plenty of attention due to oncoming

More information on IMS and IP Communication go here 

What is IMS or IP Multimedia System ?

A standardized IP-based architecture that allows the convergence of fixed and mobile communication devices and multimedia applications.  

ims arc1

Using IMS, applications can combine voice, text, pictures, and video in call sessions, offering significant ease-of-use to subscribers and allowing service providers to drive branding through a common interface  

Defined by the Third Generation Partnership Project  (3GPP) and supported by major Network Equipment Providers and service providers.  

The standard supports multiple access types – including GSM/GPRS/EDGE, WCDMA, CDMA2000, wireline broadband access and wireless LAN.

Telecommunications convergence – VoIP, PBX and IMS

There has been rapid evolution of telecom platform over the last few decades. Starting from the the mobile phone network-enabled universal communication agnostic to actual location to present day high bandwidth high data rate entertainment/ streaming like applications. The affordable, personal communication system has converged to enterperise level secure communication systems that cater to low latency and highly secure end to end encrypted scenarios.

IP communication

Some of the positive aspects of using IP communication over traditional communication systems are :

Higher ROI( Return of investment)

ROI is a big factor for SME before making the switch to IP telephony inplace of traditional established system like landline phone and cables. However it is for a fact that once the VOIP comm system is setup , it most certainly reduces call costs by 70%.

Third party Interations

It is often a necessaity to integrate communication system with CRM (content realationship management ) systems or Sales management systems or other lead gtracking systesm which are driven from communications with possible clients or investors ( called leads). Since most web portals are on IP protocl as HTTP, VOIP fits very well, with the click to call on webpage itself among other features such as directory integration , notofoication , call scripts etc.

VAS ( Value Added Service)

Value Added Services , refer to services build on top of existing underlying mobile communication call and sms. These could be innovation usecases build using -IVR / DTMF such as cricket score, astrology updates or call recoring , find-me-follow-me applicatoion for multiple devices , voicemail/ visual voice mail , re-routing to home phone or assiatnt phone, called ID etc. In short it can add intelligence to the way calls are managed .

As bandwidth has increased, so has the proliferation of VoIP systems. From the user’s perspective, modern mobile devices deliver the converged, multi-media communication and entertainment experience.

VOIP

VOIP , short for Voice over IP , is called so beacuse it not only converts your voice calls in analog voice into digital packets but also channels voice data through IP networks such as LAN , WAN , Internet etc using the Internet Protocol (IP) .

  • VOIP system on LAN ( Local Area Network ) can use it as its backbone system to establish communication between endpoints . For example : Office communication system within the same enterprise/building.
  • Similarity  VOIP over WAN ( Wide Area Network ) use the help  of IP PBX and VoIP service provider to enable communication across Internet . For example : OTT providers and internet calls.
  • By using the services of telecom providers in support with above plan it is also possible to land a VOIP call onto a real phone over GSM / PSTN via gateways.

For a provider of IP telephony system, number of factors come into picture such as :

  1. Bandwidth : Low bandwidth has always been a big concern for IP calls especially due to packet loss and thus high noise. While a LAN connection ensures good experience, calls over internet or VOIP PBX are not necessarily as neat. Network switching between different Internet service providers causes congestion and lags too.
  2. Inter-operability : Connecting remote works / employees to the VOIP network requires interoperablity between their hand held device like android , ios , tablets , smart watch or other types od communication devices such as hardphone, desktop-systems , kiosk , surveillance cams etc is a challenging considering the underlying OS and networking support.
  3. Traffic: Maximum simultaneous call or peak traffic rate can create bottlenecks in communication channel or worse still result in high bandwidth usage. For example as p2p conf call between 5 parties will create a mesh network between each participant resulting in 4 outgoing and 4 incoming channels.
  4. QoS (Quality of service ) :
    • Call drops ,
    • prioritization of important calls ,
    • Security preventing the attacks and hacks ,
    • keeping information secure by encryption end to end
  5. AAA : managing Authentication, Authorization and accounting
  6. Reuse existing Hardware :
    • Replacing old hardware or installing softphone apps on mobiles etc .
    • Reuse old servers . Manage setup between datacentres and cloud deployments
    • Administravtive hurdles between different counteries and geographies for using hardware
  7. Scaling
    • How quickly can it scale up or scale down ?
    • Will the communication system grow horizontly or vertically ?
    • How to ensure that the growing system can accommodate new users , physical office location , remote centers , call centres etc ?
  8. Codecs : Under low bandwidth condition it is a good idea to switch to low resolution ( in case of video ) and low bandwidth codec ( in case of audio ) .

Other factors such as privacy , accounability , Lawful interception ( legal requirnments in many enterprises ) , Auditing , SLA ( Service Level Agreements) to ensure the system is up 99.99 % of time and agrreeing to pay compensation if system is down for longer duration than 0.01 % of time so on.

Hosting the PBX

Unified communication Solutions as SaaS or IaaS refer to on-premise or cloud-hosted IP PBX Solutions. Comparison of both is as follows

On -premiseCloud Based
The solution is usually of the SaaS nature ( software as a service ) which is hosted by the consumer / business unit itself . The service provider offers his infrastructure to the consumer as a service and bills monthly / yearly etc .
Hosting the solution system on premise and setting up the infrastructure means more customization and flexibility but it also means more investment and maintenance . On the other hand hosting the solution on cloud is often a quick setup with relatively lower upfront payment. The billing is either carried out per per user basis or based on consumption . The data is synced to cloud servers for storage and can be fetched from there when required such as cloud synced Call-logs or contact-book .

Convergence Vision 

We already know some of the latest trends of industry with respect to telecom convergence such as :

FMC

Fixed Mobile Convergence (FMC) stands for integrating user’s fixed desk phone with his mobile phone. Call continuity is a VAS( Value added service ) which lets him to switch calls between different call devices even softphones , mid call also. It has multi-faced advantages such as not missing any call on account of being out of office , having the same call preferences on each device such as blocked numbers , IVR settings etc .

UC

Unified Communication(UC) refers to the accessibility of all communication and collaboration services from the users call agent ( phone / soft-phone ) . These services can include file transfer , chat , conference , call settings , blocking , white-listing , fax , cloud sync , call logs , called ID , favorites , recording .
Read more about Unified communication and collaboration here .

BYOD

Bring your own device (BYOD) is one of the hottest trends in industry almost across all domains where user is expected or is given to option to bring his personal laptop for official use . It is the responsibility of enterprise comm system to seamlessly integrate it with in-office communication system and provide the same privileges and security to business critical applications as preset in configuration settings . It increases the flexibility and productivity while keeping the infrastructure cost down.

IMS provided Network Interoperability and Access Independence

ims-access-network-independence
Image Source unknown. Represents the convergence of IMS subsystem with various access types

IMS based tele-coommunication convergence described in figure below

  • clients get direct connectivity to IP PBX in offices or hotels
  • home users connect through cable wires or Wifi/WiMax
  • non SIP based legacy endpoints connect via signalling and media gateways

The access endpoints connecte to a single managed core IP network which intercoonectes with IMS core . The back end system not only manages calls and sessions but also registration  ,  billing , operations and adminstartion.

IMS convergence vision
picture courtesy – unknown

 Intelligent Network   —>    Next Generation IMS System 

The signalling protocols migration like from signalling system 7 (SS7) to session initial protocol (SIP) have been taking place in Telco-Industry. Similarly nodes of legacy network like signal transfer point (STP) of legacy network are being migrated to call session control function (CSCF) of IMS  that allows the rapid development and deployment of enhanced, revenue-generating multimedia services for fixed, mobile and cable operators.

IMS architecture enables operators to seamlessly run a plethora of next-generation converged services over their fixed, mobile and cable networks, achieve a faster time-to-market for new services and have fewer performance bottlenecks.

converged telecommunications

Business benefits of IMS 

  1. Delivering Services: Delivering services and applications on a “wherever, however, whenever” basis.
  2. Multimedia services: Enabling service providers to offer multimedia services across both next-gen, packet-switched networks and traditional circuit-switched networks.
  3. Protocol stack: IMS architecture provides pipes and protocols onto which service providers can attach no. of applications very conveniently.
  4. Open Source standard: IMS architecture is based on open standard which makes it possible for different vendors of hardware and software to integrate with each other seamlessly.

As a subscriber, one of the main benefits of the IMS architecture is the capacity of the network to deliver the same set of services whatever the access network used.

convergence

This is made possible thanks to the centralization of the service execution process. A specific call server of the control plan (called Serving Call Session Control Function, S-CSCF) is responsible for invoking the application servers based on criteria provisioned in the central database. The S-CSCF gets these criteria (called Initial Filter Criteria) during the user’s registration in the IMS network.

Circuit Switched Voice –> Packet based VOIP 

Voice over IP revolutionized in the Telecommunication space.It also makes your communication experience much richer and nicer with a series of enhanced features and extended possibilities. The no. of user migrating from traditional circuit switched network to IP has been quite substantial in recent years. CSP are embracing VOIP technology as a potential revenue generator and investing huge chunk of money to create value propositions for themselves in VOIP.

In conclusion here are the top business benefits of adopting a converged and unified IP telephony solution such as IMS and SIP are

  • Cost Savings : Saving money is the number-one reason most businesses and households make the switch to a VoIP system, VoIP systems don’t require a phone cabinet or on-site routing equipment- just phones.
  • Features: VoIP also allows users to take advantage of advanced features only available on internet-based phone systems. Features like online call monitoring, and online phone system access to add or configure extensions are also available with VoIP systems.
  • Flexibility: VoIP allows people to go mobile and call directly from their cell phone and be charged at low VoIP rates
  • Tracking Options: Since VoIP is an internet-based system, user can track and manage their system from their computer. Most VoIP systems allow user to track call volume and call time fairly easily- a feature that can be especially helpful for businesses that bill clients hourly or for time spent on the phone.