Understanding VOIP Peers

[jrhofman]

I have a number of questions on an h.323 gateway configuration.

1.

I have a 3660 connected to a PBX via T1 CAS. I have the necessary pots peers to send digits to the PBX. If I configured CM to send a string of digits to the Gateway for an outbound call (IP Phone to PBX) is it necessary to have (some kind) of VOIP dial-peer in the gateway pointing back to CM for the call to work properly.

2.

I have an h.323 gateway configured in CM that is pointing to an IP address of a gateway that CM cannot ping, yet I can place an outbound call on the gateway via an IP phone and ring a station off the PBX. How is this possible.

3.

What is required to provide ring pack to an IP phone when placing calls out an H.323 gateway to a PBX with T1 CAS. I generally place an ( progress_ind setup enable 3) statement on my Pots peers but I thought this was for ringback on calls placed from the PSTN in. I am placing calls from IP phone out the gateway an am getting no ring back.

4.

Lastly, My 3660 dos not allow me to us the (progress_ind setup enable 3) command on the pots peers. Only options are the two below.

progress_ind progress enable 8

progress_ind connect enable 8

Will these commands do the same thing. Version of code on the 3660 is 12.1(5)T10

Thanks in advance for any insights.

[nmilojevic]

Hi!

One by one...

1.

You certainly need also a VOIP peer on 3660, but not in order to point back to CM. Every established call through GW has two call legs; VOIP and POTS. One of them is incoming and the other one is outgoing. So in case of IP phone calling to PBX, VOIP peer will be incoming and POTS outgoing.

It is possible of course to mix them and use them as both - incoming and outgoing, but I prefere not to.

So for example, if PBX phones have 4 digit numbers starting with 5, you should have something like this:

dial-peer voice 1 voip

incoming called-number 5...

dial-peer voice 2 pots

destination-pattern 5...

prefix 5

port 1/1:D

As you can see, VOIP peer does not point back to CM, it receives call from CM (or anyone else, actually).

Now, if you want to send calls from PBX to CM, you will need inversed situation - incoming POTS peer and outgoing VOIP peer. Now in this case, VOIP peer will point to CM with command

session-target ipv4:A.B.C.D

2.

Most probably, you can not ping the GW because some firewall along the way (or the GW itself, or the firewall on CM if you have one) blocks ICMP packets, so the GW is not pingable. None of my machines replys to ping, but they still do their job.

3.

Hard to tell without some more info. You should play some more with this commands and see what happens.

4.

Don't know. Try, and you will see?

And you could upgrade your IOS to something a little more up-to-date, couldn't you? Often helps!

Regards,

Nikola

[dhccoid.com]

The commad for POTS dial-peers is as follows.

!

dial-peer voice 9 pots

destination-pattern 9T

progress_ind alert enable 8

direct-inward-dial

port 0/0:15

!