Switchover time to SRST

[newmarket25]

I am wondering, when the connection to CCM goes and the phones go into SRST:

Do I lose any calls in progress? (Let's say the call comes in on a POTS line in a 2801 and the 2801 is hooked into the 3560 configured as H323 that my phone is plugged into).

We have 7960s with 7914 "sidecars", and of course, all the buttons light up while it tries to reconnect to CCM. During this process, I don't believe I could be taking calls.

So just wondering, when we lose CCM, and the phones light up, do we drop in place calls like I described, and can we make/take a calls while it is trying to reconnect to CCM and about how much time do you think before the phone settles into SRST mode (gives up trying to hit CCM)?

[Brandon Buffin · Accepted solution]

In general, it takes 3 times the keepalive period for a phone to realize it has lost connection with CCM. The default keepalive period is 30 seconds. The fallback process can take another 10-20 seconds. The time can also vary depending on phone type. Calls to the PSTN are not maintained by default, but may work with the "no h225 timeout keepalive" command. However, this command is not officialy supported for call preservation. Take a look at the following link for more details regarding SRST.

http://www.cisco.com/en/US/products/sw/voicesw/ps2169/products_configuration_guide_chapter09186a00806674d2.html#wp1048437

Hope this helps. If so, please rate the post.

Brandon