This post is deals with some less known real world implication of developing and integrating WebRTC with telecom service providers network and bring the solution in action .The regulatory and legal constrains are bought to light after the product is in action and are mostly result of short nearsightedness . The following is a list of factors that must be kept in mind while webRTC solution development .
WebRTC services from telecom provider depend on the access technology, which may differ if the user accessing the network through a third party Wi-Fi hotspot.
User/network type may also dictate if decryption of the media is possible/required.
For Peer-to-Peer paths, media could be extracted through the use of network probes or other methodology
Then there are Other Considerations such as specific services, for example if WebRTC is used to create softphones software permitting users to receive or originate calls to the PSTN, the current view is to treat this as a fully interconnected VoIP service subject to all the rules that apply to the PSTN – regardless of technologies employed.
Communications Assistance for Law Enforcement Act (CALEA) , a United States wiretapping law passed in 1994, during the presidency of Bill Clinton.
CALEA requirement for an LTE user may be very different than the CALEA requirements for a user accessing the network through a third party Wi-Fi hotspot.
For media going through the SBC, CALEA may use a design similar to existing CALEA designs.
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 agent
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 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 .
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 .
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.
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.
Services part 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
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.
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.
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.
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 .
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.
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.
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.
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
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
Extracting data from multiple sources and vendors , that includes legacy systems
Extracting data due to its large scale and volume
Creating an effective knowledge share and transfer for live operations
Training in fallback plans, standards and policies .
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
Pilot program and real network simulation for ensuring preparedness
The telecom landscape has evolved, as far as infrastructure, services and contents are concerned. Industry is witnessing a migration from Legacy to NGN. Next Generation Network (NGN) is being implemented globally as a means to change the cost base, agility and service capabilities of telecoms providers. The evolved architecture for the transition is one that provides flexibility to service providers by enabling them to deploy new services on IP based technologies, while leveraging existing services and infrastructure as long as it makes sense.
This post describes the evolution of voice communication in access ,transport and session layers respectively.
We know that Service broker is a service abstraction layer between the network and application layer in 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 .
The service provider can combine the services from various sources written in various languages in numerous permutations and combinations . This saves the time , energy and rework required to launch a new services.
I believe and it truly is a wonderful thing to make use of Service Broker while network migration from IN to IMS .The following architecture model depict the placement of Service Broker component in IN and IMS integrated environment .
The figure above portrays how a service provider acts as a central Node for Services invocation and services composition. SB is responsible for Services Orchestration / Interaction , service development, third party integration and acts like a protocol gateway .
Let us discuss service broker in a full fleshed network’s structure . It includes the access network components and detailed core network components with the name of interfaces between all nodes.
The Applications as described by the above figure could be majorly of 4 types :
1. applications developed on a SIP application Server and invoked via SIP/ ISC
2. Applications developed over SIP servlets or JAINSLEE platform such as mobicents , Opencloud Rhino etc
3. Application developed on a SCP ( Service Control Point ) of a IN ( Intelligent Network ) . This is invoked via INAP CS1/CS1+ or CAP
4. Application developed on a J2EE server Invocated via http REST API like GSMA OneAPI such as
Call Control API for voice.
Messaging API for SMS, MMS.
Provisioning via fixed/mobile brands & « service profile» in SB