The Case for Instrumenting the VoLTE Network

VoLTE Lessons from the Field

network engineer

The rollout of VoLTE has long been trumpeted as ringing in a new era of mobile voice communications. With VoLTE, operators complete their network and service migration to an all IP-based infrastructure with all the flexibility, cost savings, and benefits of IP networking. But VoLTE is also a disruptive technology that will surely test the Network Engineering and Operations teams in mobile service providers. To assure the success of this new service introduction, the case can be made for over instrumenting select market in the first market VoLTE rollout with service assurance gear.

We have all seen the logical network map for VoLTE (fig. 1) picturing the eNodeBs to MME for radio attachment, and then onto the HSS for Authentication (AAA), the MME to the S-GW handling the session establishment and bearer modification, from the eNodeB to the S-GW, onto the P-GW for the user plane transport, and so on through hand-over of the VoLTE sessions from the LTE network to the IMS network. However, it is the actual physical path with all of the intermediary routers and switches between these LTE elements that concerns us, in order to assure that all of the ingress/egress points are properly functioning for VoLTE.

All of the in-and-out between the routers, switches and gateways (the interaction between devices) should be monitored ideally in the first market to gain the full visibility to the VoLTE session paths. With this approach, operations teams can see and understand all the potential issues with DSP markers, QoS mismatches, Out-of-Sequence packets, 1-way audio, and other possible network impairments that may need to be discovered and quickly remedied. From this learning experience, operators are able to offer first-market participants a better service, faster, so similar issues are less likely to be repeated in the other markets when and where VoLTE is rolled out.

Simply put, visibility is critical to assuring the successful delivery of VoLTE. Your service assurance solution for VoLTE must not only be end-to-end, but also provide hop-by-hop advanced analytics and service triage capabilities.