Transforming Interconnect for IP Networks

In traditional interconnect, every telecom operator has domestic and international partners to terminate traffic, or use hub operators to route the traffic to specific destinations using time-division multiplexing (TDM) circuits. But with full service IP networks coming into the arena, telecommunication operators can provide video, data and voice using the same backbone network structure. Over the next few years the traditional TDM/PSTN and IP would probably continue to coexist. Interconnection in effect also undergoes a transformation here. Interconnection creates end to end service connectivity and interoperability across providers.

As the industry is transiting into a hybrid model where IP coexists with TDM, the physical infrastructure for call transfer and exchange is undergoing a technological transformation. All new networks are using the IP backbone and this has lesser points of interconnection as compared with the TDM/PSTN network. The need for more bandwidth and to keep up with network trends now, focusing on accurately transport newer types of data, IP is definitely the most cost effective and sustainable solution.

The current subscriber needs and demands are seamless, ubiquitous connectivity of mobile services everywhere, giving them access to information and social data. And while today the focus is on voice and video, voice is rapidly becoming a part of other bundled packages and offerings.

The focus of past bilateral agreements between telecom providers were typically based on commercials and volumes with penalty, shortfall or send/pay clauses associated. Settlements happened at a defined frequency where invoices are exchanged, compared and reconciled in cases of disputes. Quality metrics in the traditional interconnect model were parameters like ASR, NER, etc., which sampled/monitored data to derive the call quality and checked periodically for SLA violations and route failures. At this stage, the IP layer was merely handling transport, while the actual services (be it voice, content, OTT, or web based) would be delivered in any combination. With IP related services becoming a predominant offering, it means the understanding of quality, routing and agreements would change dynamically over the next few years and lead to the need of a ‘new’ interconnection model that would be able to handle these level of agreements, charging and settlement. Quality of service for IP now needs to prioritize data security, encryption and protection of information.

The target being constant connectivity, another challenge in terms of both technology and business is roaming agreements. Initially GPRS roaming required complex agreements between every individual operators and each operator had to maintain dedicated links. GSMA had launched GRX (GPRS Roaming eXchange) technology a few years ago to handle mobile packet delivery and exchange. This started off supporting 2.5G technology and eventually 3G as well. The idea behind this was to ease roaming agreements between GPRS vendors. GRX is typically based on a public IP backbone and used GTP (GPRS Tunneling Protocol) and enabled the GRX operator to act as a hub for the interconnect partners without having direct or dedicated links between them. GRX is making way for IPX (Internet Protocol eXchange) which addresses some of the drawbacks of GRX. Primarily MNOs could leverage the benefits of GRX and this was a model based on best effort, hence QoS, security, acknowledgement were not guaranteed in this method.

IPX on the other hand, has clear quality parameters like Service Availability, Jitter, Packet Loss and Delay. It also has defined traffic classes: Conversational, Streaming, Interactive and Background Class, so any kind of application has to be clearly mapped to a potential QoS class name, for example: Instant Messaging is Interactive, Video is Streaming while File Transfer is Background. Telecommunication operators with backbone network would look at offering an IPX solution to mobile operators, content providers and aggregators by supporting multiple data, video and voice services. Mobile operators earlier had to rely on multiple platforms for voice and data and can now look at a unified synergy. The target market would look at not only MNOs (Mobile Network Operators), but also MVNOs (Mobile Virtual Network Operators), Content Providers, App Providers, Fixed Line Providers.

With IPX built on a secure IPVPN network, a lot of the parameters around security and protection would be eliminated, while all kinds of data can traverse through a standard backbone network. Operators need to focus on sustainable revenue models. A strong settlement and assurance system would be critical in this play to understand the packetized data structure and price based on the CoS (Class of Service).

This article was originally published on the Subex blog. It has been reproduced with their permission.

Debolina Ray
Debolina Ray
Debolina is a seasoned professional who specializes in partner settlement, route optimization, interconnect billing and order management/provisioning. She currently works as a Technical Product Manager for the cost analytics portfolio of Subex.

Debolina is an active contributor on various forums like Actuate and QlikTech. She is also a voracious reader and an active blogger.