I just set up a VoIP network with Cisco routers 1750, 2600, 3600 and 3810 as gateways, a Cisco 3600 as a gatekeeper and a few ATA186.
On the gatekeeper the IOS version is c1700-sv3y-mz.122-4.T1 on the Gws 3600 the IOS is c3640-is-mz.122-28a, on the 3810 mc3810-a2isv5-mz.121-5.T9,on the 2600 c2600-ik9s-mz.122-17a and on the 1750 I am using different versions like c1700-sv3y-mz.122-4.T1 and high.
Everything is working fine except the long delay of 10 to 15 seconds to hear the first ring after place a call.
This happens only between gateways. From gateways to the ATA186 or vice versa or between the ATA186, I hear the ring immediately. So, how can I reduce this delay? Thanks.