Pblem with analog interfaces

n.morelli · ‎07-10-2001

Hi, i've a problem with a multisite test environment.

We've a central office and two branch offices.

On central site there's a 3660 with an FXS interface and a CallManager with 5 IP Phones.

When i call the analog phone on the fxs from ip phone, from ip phone i can hear the analog but not vice-versa. I tried to change the interface fxs,NM-2V but no result yet.

Regards.

dgoodwin · ‎07-10-2001

From the 3660, are you able to ping the address of the IP phone?

If not, then it may be that the router and the phones are on different subnets and the IP phones do not have a default gateway configured.

spodonnell · ‎07-10-2001

Dave,

I have the same problem.

I have a 1750 router with fxs analog phones connected in a branch office.(centralized CM design) If I try to call between the analog fxs and an ip phone on the local ethernet segment, I only get one way audio.

If I call the fxs extension from any other location, it works fine. If I call one of the ip phones from another location, if works fine.

It seems to be an issue of how the local router creates the stream from the FXS back to the IP phone.

I'm using the H323 bind command referencing a

loopback address but I'm wondering if the router is sourcing the FXS rtp stream from the wrong interface.

dgoodwin · ‎07-10-2001

Yes, the h323-gateway bind command is exactly what you need to do to fix the problem you describe. Is it possible that before you had implemented that command, you had already created an H.323 gateway in CallManager that pointed to one of the "real" IP addresses on the router, and that is still where you are routing the calls in the CallManager route pattern? If so, that is the problem.

n.morelli · ‎07-11-2001

Hi,

thanks a lot for your answer.

In my test environment the 3660 and the CCM are on the same subnet. The DHCP service is installed on the CCM.

If i try to connect the analog phone on branch office router's FXS i've the same problem.

Regards.

tonygauderman · ‎07-11-2001

I am assuming that the gateway is configured in H.323 mode and that you have not issued the following command on the Ethernet interface

h323-gateway voip bind srcaddr ipaddressofh323phone

Once you do this, the router will use the address you specify as source address for h.323 calls. After you make secondary addresses on the ethernet interfaces for callmanager to use for the analog h.323 phones you are configuring on the gateway, bind the srcaddr to one of those addresses and all should work fine...

n.morelli · ‎07-12-2001

Hello, I not understand, I must add the command

h323-gateway voip bind srcaddress, the srcaddress what address is? The ethernet?

Regards

dgoodwin · ‎07-12-2001

Yes, the IP address will be the IP of the interface itself where you are configuring it. For example:

interface FastEthernet0/0

ip address 10.1.1.1 255.255.255.0

h323-gateway voip bind srcaddr 10.1.1.1

n.morelli · ‎07-13-2001

Thanks a lot.

The customer where I had this problem is in another city thus I try and then inform you on the results.