Receptionist experiences audio delay before she can hear the customer

[troymaki]

The setup is an 1861 with 5 IP phones. I am running version 12.4(22)T The receptionist is saying that when some calls come in from outside customers, she intermittently has a delay of 10 seconds before she can hear the caller's voice. What would cause this to happen? The config of the 1861 is attached. Thanks

[Nicholas Matthews]

What's the call flow?

Something like:

7965--Fa0/1/0--1861---FXS---PSTN

Or

7965--Fa0/1/0--1861--Fa0/0--H323--CUCM--MGCP--GW--PRI--PSTN

[troymaki]

It should be like this:

7965--Fa0/1/0--1861--Fa0/0--H323--CUCM--MGCP--GW--PRI--PSTN

The Call Manager is located in my office. It is version 6.1.1.2000-3.

[Nicholas Matthews]

On CUCM, you can try two things:

On the H323 gateway:

Check MTP required

Enable Outbound Fast Start

and

Enable Inbound Fast Start

Sometimes we see long delays with H323 is required to do slow start.

Otherwise, it would require getting mgcp/pri debugs from the far end gateway, CCM traces, and H323/ccapi debugs from the 1861 - which is messy.

hth,

nick