SRST Configuration

[lambay2000]

Dear Experts,

Attached is the configuration for the router who is acting as SRST for CUCM 9.1. SCCP phones get registered when connection is lost with CUCM but sip phones(3905) doesn't.

Do i need to enable a telephony service on the SRST router for the SIP phones to register.

Thanks

[Jaime Valencia]

Have you configured SIP SRST??? The SRST configuration guides covers both, SCCP and SIP, this has been discussed very recently with some examples on CSC you can easily find.

[lambay2000]

Dear Jaime,

You are the expert in CSC, that's the reason i posted my configuration, did you see anything missing in the configuration,

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cusrst/admin/sccp_sip_srst/configuration/guide/SCCP_and_SIP_SRST_Admin_Guide.html

please suggest.

Thanks

[George Thomas]

Did you populate the SIP address in the SRST reference on CUCM?

[lambay2000]

Dear George,

Yes it is already done my 7942 phones fallback to srst mode but 3905 doesnt,

just referring the compatibility of firmware on the phone when they fallback on the srst mode.On SRST the firmware supported is 9.2 for 3905 phones and for 7942 phones is SCCP42.9-2-1S.loads.  And on  CUCM 10.5 they are running on 3905 9.4 and 7942 SCCP42.9-3

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cusrst/requirements/guide/srs91spc.html

7942 SCCP phones fall back to srst mode without any issue, but sip phones do not, if for some moment we think for firmware compatibility issue then that shld affect to 7942 phones as well

[George Thomas · Accepted solution]

SRST references have two address fields in CUCM - one for SCCP and other for SIP. Are you sure that both are populated is my question?

[lambay2000]

Dear George,

Attached is the snap shot.

[George Thomas]

Why is it set to 93.0 and not 93.5? On both CUCM and GW.

[lambay2000]

Dear George,

what i thought that i have to specify the sip phones network and not the SRST router ip address, i have change to SRST ip address 192.168.93.5 and will reply back to you in 5 min

[lambay2000]

Dear expert,

thanks sip phones fall-back  to srst mode,

[George Thomas]

Thanks for the rating and good luck!

[lambay2000]

Experts,

SIP phones are registered in srst mode but there is no calling between sip to sip 3905 phones and also there is no dial-tone on the phones. i see a exclamation (!) mark beside the extension on the phone.

Thanks