Few Phones going in and out of SRST Mode

[JWALBERTINI]

Having an issue were five phones at a remote location went in and out of SRST mode.  No hits on the WAN, and no issues with CUCM.  Looks like a LAN issue but, phones are on different switches.  Anyone experience this, any thoughts?

[Jaime Valencia]

Look at CUCM app logs for the disconnect reason from those phones.

They won't go to SRST unless the keekalives are not being acknowledged or the TCP link to CUCM is broken.

HTH

java

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[syedmd866]

Hi,

Please let me know, in few locations our IP phones are going to "preservation mode". Once hangup it is resolving.

What is preservation mode ?

Thanks.

[Emmanuel Akum]

Did you determine what was pushing the phones to preservation mode, when the call is hanged up? We've got a similar scenario with calls between SIP phones and H.323 Voice gateways. (Calls between SIP phones on-prem and an external /PSTN participant)