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Two weeks ago, RADVISION hosted the IMTC SuperOp! 2008 event. The most obvious conclusion from this event is that multimedia conferencing (or should I say Unified Communications) is getting better – at least in terms of interoperability. Without exceptions, all companies successfully connected video sessions with one another.

The IMTC SuperOp! event is the main interoperability event of the IMTC. In this event multiple activity groups, each dealing with a different multimedia communications technology, gather in a single room to test products enabling communications across the globe.

As event hosts, it was a complex event, mainly from a networking point of view, as there were many requirements that had to be met:

1. Internal internet connectivity (between participants)
2. External internet connectivity through ADSL (communicate with the outside world)
3. Wireless LAN connected to the internet
4. SDSL for larger uplink for some activity groups
5. Internal ISDN lines (BRI and PRI) for the ISDN products
6. 3G USIM cards for video telephony for the 3G products
7. 3G USIM cards with data packages for the 3G products
8. External ISDN lines, with connectivity to the 3G network

The above requirements meant dealing with multiple service providers – mobile, telephony and cable. Why were they needed?

3G Video Telephony

For 3G video telephony (3G-324M) there’s a need for 3G USIM cards (which limits the testing to Europe and Asia, as there is no support in the US for it). Most handset vendors can only test using 3G cards.

Companies who develop servers require ISDN connectivity (usually PRI), and can only test with handsets if there’s connectivity on the service providers side between 3G and ISDN.

Those running their application from a PC can use either 3G or ISDN – whatever suits them.

Mobile Streaming

Mobile streaming (PSS or RTSP) is done in an asymmetric manner – servers on one hand and clients on the other.

The servers usually run on PCs and need to be located in the testing premises – it provides easy debugging and enables the use of network simulation tools. These PCs are connected via Ethernet to the outside world and are used to stream video to the clients. This means that their upload bandwidth needs to be high (hence the need for SDSL). These servers also need to be accessible through the internet, so they require static public IP addresses.

The clients are handset-based and require 3G USIM cards to operate. As PSS is an IP-based activity, the 3G cards also need to have “generous” data plans (to allow testing for a full week, 8-10 hours a day, streaming video to the handsets).

Video Conferencing

Video conferencing (H.323 or SIP) is the reason the IMTC was established in the first place, and is still tested today. Traditionally the focus of the testing was the diversity of protocols and connectivity (for instance, reaching other networks, such as the 3G, using gateways). In the past few years, focus has also been put on high definition video.

This testing usually requires good internet connectivity inside the testing premises (as there are a few high definition conferences being tested at the same time) as well as enough ISDN lines to check against the legacy H.320-based endpoints.

Robustness

Setting up the network and catering the needs of all these groups was not easy. It took almost two days to get the testing infrastructure stabilized enough, and we still had 3G reception issues due to the load over the mobile operator’s network.

What was evident during the week of testing was once you get the network up and running, participating companies were immediately able to test successfully, and were able to focus on the testing areas they wanted to. This is an indication to the robustness of the current protocols and implementations.

That said, the fact that there is so much diversity in the protocols (access networks and technologies that are used) is not making the lives of developers (or consumers) any easier. Past talks about convergence seem more like a hype than reality, and I am afraid that the same will become of the new “Unified Communications” hype. We will see some more integration between different products and technologies, but at the end of the day diversity will be an issue as it is today.