Secure Real-Time Transport Protocol - Avaya Nortel Communication Server 1000 Manual

UNIStim
The Unified Network IP Stimulus protocol (UNIStim) is the single point of
contact between the various server components and the IP Phone.
UNIStim is the stimulus-based protocol used for communication between
an IP Phone and an LTPS on the Voice Gateway Media Card or Signaling
Server.

Secure Real-time Transport Protocol

The Media Card 32S card uses Secure Real-time Transport Protocol
(SRTP) to secure the IP media path between the card and the Nortel Phase
II IP Phones, IP Phone 1110, IP Phone 1120E, IP Phone 1140E, or IP
Phone 1150E, IP Phone 1210, IP Phone 1220, IP Phone 1230, or another
Media Card 32S card, or a DSP daughterboard. When Media Security is
configured to On, the Call Server sends a message to the Voice Gateway
software on the Media Card 32S card to activate SRTP for the media
connection established for that call.
Media Security is configured by the system administrator.
For information about SRTP, see IP Phones Fundamentals (NN43001-368)
and System Management Reference (NN43001-600).
ELAN TCP transport
Although TCP is used for the signaling protocol between the Call Server
and the Voice Gateway Media Card, RUDP remains for the Keep Alive
mechanism for the link. This means that RUDP messages are exchanged to
maintain the link status between the Call Server and the Signaling Server
or the Voice Gateway Media Card.
The TCP protocol enables messages to be bundled. Unlike the RUDP
transport that creates a separate message for every signaling message
(such as display updates or key messages), the TCP transport bundles a
number of messages and sends them as one packet.
Handshaking is added to the Call Server and IP Line software so that
the TCP functionality is automatically enabled. A software version check
is performed by the IP Line application each time before it attempts to
establish a TCP link with the CS 1000 CPU. TCP transports messages,
whereas RUDP establishes and maintains the link.
The IP Line software version must match the Call Server software version;
otherwise, IP Line terminates the link and logs an error message.
Copyright © 2003–2008, Nortel Networks
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acknowledge) message, which includes the number of the missed
packet, is sent to A. A retransmits the first missed packet and continues.
Nortel Communication Server 1000
IP Line Fundamentals
NN43100-500 02.02 Standard
Release 5.5 4 February 2008
Voice Gateway Media Cards 43