MGCP gateway with SRST. Fastbusy on inbound calls to Alias??

[tcekada]

Please see config excerpts below. When MGCP gateway is in SRST mode I get a fast busy on CALLS to two FXO ports which are set up to plar to 3200 but in SRST the alias command is supposed to forward to extension 2799 but does not. I can see the call coming in but again all I get is a fast busy. BTW the plar commands to 3200 works which the router is up.

voice-port 0/0/0

timing hookflash-out 500

connection plar 3200

!

voice-port 0/0/1

timing hookflash-out 500

Connection plar 3200

dial-peer voice 999000 pots

service mgcpapp

port 0/0/0

!

dial-peer voice 999001 pots

service mgcpapp

port 0/0/1

call-manager-fallback

max-conferences 8 gain -6

transfer-system local-consult

timeouts interdigit 3

ip source-address 2.2.2.2 port 2000

max-ephones 24

max-dn 24 dual-line

voicemail 92297865

alias 1 3200 to 2799

[lfulgenzi · Accepted solution]

Try without the alias first, eliminating at least one point of failure. See if that works. Of course, you will need a phone registered with a DN of 3200.

I suspect this is the issue, because typically you will get a dialtone if things are not configured properly.

Also, do you have:

application

global

service alternate Default

configured?

[tcekada]

I will remove the alias command as you say and put in connection plar 2799 (the DN itself). Also I do not have the

application

global

service alternate Default

configured. I take it this is important?? I will throw that in as well.

Thanks,

[lfulgenzi]

The service alternate default is very important. It's what allows the inbound calls on the FXO to be sent to the SRST process (I think).

I was on the console with logging set to debug and I was able to see inbound calls to the FXO port fail with an error like "cannot pass call to application default" or something like that.

Once I added the above config lines, it worked fine.

And the other part to remember is that the MGCP dialpeers have to be before any h323 dial peers in your config.