Problem with incoming VoIP calls

[unicum]

Hi!

Help me, please.

I use CCM_3.3(4)sr2 and PIX525_soft_6.3(1).

Scheme:

PSTN -> Voice GW(from ISP) -> PIX(my) -> CCM(my).

IP Adress:

phone number -> 10.1.0.2 -> X.X.X.X -> 172.16.0.3

If incoming call were from other CCM then all ok.

If incoming call were from PSTN, then I listening ringin my Cisco IP Phone, but I don't hear anything.

In PIX logs:

Message CALL PROCEEDING received from 172.16.0.3/1720 to 10.1.0.2/13923 before SETUP

What is the problem?

Excuse me for my English.

[Aaron Harrison]

Where is the other CCM? Also outside the firewall?

If so then (unless you have different rules set for the gateway) it sounds like you have a one-way voice issue on the Voice GW... If this is an IOS router have your ISP make sure that:

1) the 'IP routing' command has been entered into the gateway

2) the 'h323-gateway voip bind srcaddr ' command has been entered into the gateway's Ethernet interface that registers to CCM.

See this link for more info:

http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a008009484b.shtml

[unicum]

>Where is the other CCM? Also outside the firewall?

Yes!

Yes. My ISP using Cisco 5xxx series router Voice GW

But when calling entered my phone number, Hi listening from robot: "This number temporaly not working". And Hi doesn't listen ringing!

[carijit]

It may be the problem with your PIX and the Skinny.

Do you have the fixup command on your PIX for the Skinny protocol.

Also I hope when calls originate and terminate in the same Cisco cluster you are not passing those through the PIX.

Cisco 5XXX series dont support voice.

[tbekdemir]

Yes, fixup command exists in PIX for h323, skinny, etc.

we have Call manager cluster, running at stand-alone cluster mode, behind two PIX firewall running in failover mode. Are you saying that Cisco Call Manager clusters have some problem if they are behinde a PIX firewall?

we don't see any problem while two 1760 VG calls each other through PIX.

However, one AS5400 gw calls any gateway( 1760 or other AS5400) through PIX, it fails. AS5400 could not get q931-alert packet from remote gateway so we could not hear any ring or voice .

What do you mean by saying "Cisco 5XXX series dont support voice."

[carijit]

Can you post your PIX configs please.

We had some skinny firewalling problem with FWSM before which was resolved by Cisco with a special patch.

Also the previous post says their ISP uses Cisco5XXX voice routers. As far as I know theres no 5xxx series router in Cisco also if there is such router it doesnt support voice.

[tbekdemir]

Hello,

I read your problem. We have similar problem working with PIX. Could you solve it? If so, could you please explain how you did it?

Tahsin Bekdemir.

Network Admin.

[unicum]

Hi

I fixed this problem.

My ISP is using Cisco Voice Gateway.

After my ISP entered command:

"ip tcp path-mtu-discovery" on Voice GW

all working.

[tbekdemir]

Hi unicom,

after your e-mail, I tried it in our case also, then it solved our problem also.

Thank you very much...

Tahsin.

[unicum]

Not at all.