One of the things that Cisco is moving towards is really embracing SIP as a networking protocol standard. They've always had their SCCP, or the Skinny Client Control Protocol, which is their proprietary signaling protocol, and they've been supporting the H.323, but now they're really starting to embrace SIP.
And a lot of the Cisco products coming out are allowing you to use their gateway as a SIP router without having to make use of their SCCP protocol if you want to do transcoding, which is converting codecs from one quality to another, usually to conserve bandwidth. Without SIP, this transcoding still requires binding the session to an SCCP driver, resource and handle to make it work as you want.
However, Cisco is releasing a product called the Cisco Unified Border Element, or CUBE, which is a native SIP device where you can do that transcoding without using SCCP.
There's a big push for SIP compliance on Cisco's devices, which is an interesting move for Cisco because it's moving service providers away from a reliance on proprietary protocols like SCCP to an open protocol like SIP. Cisco wants to open the market to service providers that may not use Cisco products. A lot of service providers will still use SCCP, and a lot of people will still use Call Manager, and Cisco will continue to support those products because the products are more turnkey. However, SIP is becoming the open standard, and Cisco wants to be able to interoperate with other networks efficiently, and the best way to communicate between companies is to use SIP.
SCCP is useful for the local office phones on the LAN, but to have two different voice servers at two different corporations talk to one another requires a common signaling protocol such as SIP. Cisco is embracing the SIP protocol early, so when SIP peering and mesh networks become commonplace, Cisco will be ready. I think it's a very smart move by Cisco.
This was first published in May 2008