Hi all,
I've been searching for a while but can not find a definitive answer but luckily I have something that seems to work. I want to share some and ask some. Most documentation concentrate on SIP-trunk+CUBE, Classic PSTN+SRST, CUCM+SIP-trunk to Voice router, SRST with SIP phones but there's no real example of SRST on a voice Gateway with an SIP-trunk on the providerside (at least I haven't found it yet).
Our situation:
SIP-trunk (Provider)<----> Voice Router/CUBE/SRST<-----SIP Trunk---->CUCM Cluster (Publisher + Subscriber)
First challenge: Dial-peer failover
By tweaking the settings under sip-ua (Retry timers and timeout timer) you can get a decent failover of the dial-peers when one fails. The problem we encountered is that we had to enter the requested values of our SIP provider so this had to be solved in a different way (these timers are way to high for a properly timed failover). Going H.323 was one option but I found monitor probe icmp-ping. This works like a charm.
Example:
!
call fallback active
!
dial-peer voice 2076 voip
description ** incoming SIP to SUB **
preference 1
destination-pattern 0512345678
monitor probe icmp-ping
voice-class codec 1
session protocol sipv2
session target ipv4:172.16.10.2
incoming called-number .
dtmf-relay rtp-nte
no vad
!
dial-peer voice 2077 voip
description ** incoming SIP to PUB **
preference 2
destination-pattern 0512345678
monitor probe icmp-ping
voice-class codec 1
session protocol sipv2
session target ipv4:172.16.10.1
incoming called-number .
dtmf-relay rtp-nte
no vad
!
Second Challenge: SRST
Question: If i go in SRST (CME-mode) and want this number (0512345678) to fallback to extension 254. Do I have to configure a third dial-peer with an a lower preference but with an translation profile ?
Some thing like:
dial-peer voice 3000 pots
translation-profile incoming called_0512345678
incoming called-number 0512345678
preference 9
voice-class codec 1
direct-inward-dial
!
We have discontinues external numbers so a dialplan pattern is no option. I haven't tried the third dial-peer yet because then I have to disable critical dial-peers in our router (don't know why they don't like this during working hours ;-))
All phones are SCCP-based.
Thanx in advance !
