Nortel Networks NN43001-121 manual Mediation Server, CS 1000 and OCS 2007 logical network elements

20Converged Office component overview

Media gateways translate the following protocols between the circuit-switched PSTN network and the packet-switched Enterprise Voice infrastructure:

•Signaling protocol—SS7 and other protocols on the PSTN translate to SIP for Enterprise Voice

•Transport protocol—T-Carrier or E-Carrier on the PSTN convert to RTP or Secure Real-Time Transport Protocol (SRTP) for Enterprise Voice

From the Nortel perspective, the CS 1000 functions as a media gateway for the clients of the OCS 2007 server.

Mediation Server

The Mediation Server provides signaling and media translation between the Enterprise Voice infrastructure and a CS 1000 gateway.

Figure 3

CS 1000 and OCS 2007 logical network elements

The Mediation Server provides the following functions:

•translates SIP over Transport Control Protocol (TCP) (on the CS 1000 gateway side) to SIP over mutual Transport Layer Security (TLS) on the Office Communications Server side

•encrypts and decrypts SRTP on the Office Communications Server side

•translates media streams (G.711) on the CS 1000 gateway side and RT Audio on the Office Communication Server side

Nortel Communication Server 1000

Nortel Converged Office Fundamentals — Microsoft Office Communications Server 2007

NN43001-121 01.03 Standard

Release 5.0 30 April 2008

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