Nortel Networks NN43001-121 - Manual (Page 79)

Remote Call Control with SIP CTI 79
• After an event occurs that causes the IP Phones to register to a server
other than the Front End server (and then to return to the Front End
server), the Office Communicator 2007 client does not automatically
follow the IP Phone registration. To direct the TR/87 sessions back
to the TR/87 FE that corresponds to the home TPS, take one of the
following actions:
— Users must log out and log back onto the TR/87 client (for example,
Office Communicator 2007) to force the previous SIP dialog to
terminate so that a new dialog can be established, which NRS
redirects to the correct TR/87 FE.
— An administrator issues the SIPCTIStop all command on the
Signaling Server on which the TR/87 sessions currently reside
to terminate the SIP dialogs. This forces the clients to send
another association request (for example, SIP INVITE), which the
NRS redirects to the correct TR/87 FE, as depicted in
Table 16
"SIPCTIStop all command" (page 79) .
Table 16
SIPCTIStop all command
Command Description
SIPCTIStop all De-acquire all AST DNs and terminate all TR/87 SIP sessions.
Branch Office redundancy (MG 1000B/SRG)
Branch Office scenarios can be supported; however, SIP CTI support and
Telephony Gateway and Services are available for Branch User IP Phones
in Local mode (registered in the Branch Office) only when the following
conditions are met:
• The Branch Office has SIP CTI and Telephony Gateway and Services
enabled and has a Signaling Server dedicated to each branch.
• The network dialing plan is a Coordinated Dialing Plan (CDP).
• The IP Phone (Branch User) has the same domain name configured in
both the Main Office and Branch Office.
• The Branch Office has access to the NRS and Office Communications
Server (OCS). If access is disrupted, failure cases may not be supported
if the NRS and OCS are located in close proximity to the Main Office,
which is no longer available. For example, when the WAN link to the
Main Office is down, the NRS and OCS are out-of-service.
• The SIP Gateway in the Main Office is out -of-service (in which case the
SIP Gateway in the Branch Office is used).
Nortel Communication Server 1000
Nortel Converged Office Fundamentals — Microsoft Office Communications Server 2007
NN43001-121 01.03 Standard
Release 5.0 30 April 2008
Copyright © 2005–2008, Nortel Networks
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