A South African IP Voice Network Operator needed to implement a transcoding solution to ensure calls switched between networks maintained the highest call quality despite disparate codecs.

The Problem

In order to maintain the highest possible call quality to it’s customers a South African IP Voice provider needed to centralise the control of codec negotiation between their customer’s legacy endpoints and various local interconnect partner networks. He company turned to PerfectWorx Consulting to assist in implementing a transcoding solution. on their existing Oracle Communications Session Border Controllers (previously known as ACME Packet Net-Net series)

Key Project Objectives

* Handle the complexity of network connections and the range of media codecs

* Optimize bandwidth availability by enforcing the optimal compression codecs and packetization timers

* Normalize traffic in the core network to a standardized codec

* Ensure interconnection agreements between peer VoIP networks use only approved codecs

The Solution

Transcoding is the ability to convert between media streams that are based upon disparate codecs. PerfectWorx Consulting’s expert engineers were able to implement a transcoding solution on Oracle Communications Session Border Controllers (previously ACME Packet Net-Net series), which support IP-to-IP transcoding for SIP sessions, and can connect two voice streams that use different coding algorithms with one another.

By providing transcoding capabilities at the network edge PerfectWorx Consulting was also able to provide a greater degree of flexibility and control over the codec(s) used in the customers network and the networks with which they interconnect. In addition, this configuration ensures that transcoding can be performed on the ingress and egress of the network.

Particularly important to the customer was the ability to enforce packetization time values of the media streams in order to communicate with networks that only accept specific ptime values and to optimize bandwidth across the network.

Engineers mapped out the specific codecs and associated ptime values for each interconnect network ensuring that the appropriate transcoding and transrating rulesets were applied per interconnect realm.

Solution Summary

The implementation of the transcoding solution provided the customer with the following benefits:

* Flexible networks standards ensuring that new customers could be added to the network regardless of their equipment codec standards

* Bandwidth optimisation in the core of the network by enforcing optimal codecs and ptime values

* Normalizing traffic at a single location in the network to improve control

* Honouring interconnect agreements by utilizing only approved codecs