No if the WAN is down the call manager has no way of performing call setup or disconnects for the branch phones. Hence the SRST functionality. Basically phones need to be configured with SRST to allow them to know call out. The hardware platform of the router determines how many phones are supported in SRST mode. After a certain amount of time in which the local router cannot contact the CM it triggers SRST mode and phones that have been configured are allowed basically phone functionality such as outbound calls via the PSTN.<br>
<br>Hope that makes sense.<br><br>Karen<br><br><div class="gmail_quote">On Fri, Dec 11, 2009 at 8:15 AM, anand <span dir="ltr"><<a href="mailto:anand.eee@gmail.com">anand.eee@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi,<br>
<br>
I have been breaking my head to understand the exact functions of SRST.
During the WAN failure, SRST router takes PSTN path.My question is
during this time will the call manager controls the call or Call
Manager is completely out of operation(I mean it does not take any part
in the call control on the PSTN path).<br>
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