The CME can not registerd to CME

[gushuhua]

Hi，

 we are facing issues with registration about Cisco IP phone CP 7821 with CIsco router 2921。 The IP phones are on the branch and CIsco router 2921 are on the headquarter.There is an WAN dedicated line between the branch and the headquarter。 We have the following IOS versions:

cisco IOS version: Version 15.2

CME version：11.6
Cisco IP phone : 7821

when the WAN link failes and recoverd , the phone can not registerd to the CME automatically. We need to reset the access switch port which the phone connected on the branch and clear the Firewall session connection on the headquarter。

Why the ip phone can not registerd with CME automatically when the network connection recovered? How we should optimize the network config ?

[M02@rt37]

Hello @gushuhua,

SCCP or SIP firmware ?

[gushuhua]

The phone used SIP firmware .

[M02@rt37]

Thanks @gushuhua,

do you have log for about that issue ?

[gushuhua]

There's no logs about that issue and it occurs the fisrt time.

[Nithin Eluvathingal]

7821 are SIP phones and dont support SCCP.

[M02@rt37]

Right @Nithin Eluvathingal!

There's no Skinny for 78xx nor 88xx nor newer IP phone models.

Thanks for that clarification.

[Nithin Eluvathingal · Accepted solution]

You need to check from the firewall "We need to reset the access switch port which the phone connected on the branch and clear the Firewall session connection on the headquarter。"

Make user the SIP inspections is disabled on firewall.  if not disable and try.

[gushuhua]

Thank for your suggestion, I will check it.