[cisco-voip] Audio cut-through delays upon transfer

[James Andrewartha]

On 13/01/17 09:25, James Andrewartha wrote:
> We've experienced something similar for about 2.5 years, on some calls
> one party won't be able to hear audio for 5-10 seconds. These are all
> internal calls, single site, phones (7965 and 7975, SCCP) on a flat L2
> network, one pub, one sub. It even survived an upgrade from 8.6 to 10.5.
> We opened a case and TAC asked for a trace of it happening, but we
> couldn't reproduce it easily. I keep meaning to get back to it, but
> haven't had the time given how hard it is to reproduce.

Well, some staff have moved to a demountable with a switch daisy-chained
from another and it's happening quite a bit now. Looking at the CDR I
can see that one end is just not receiving the packets. The phones are
on the same subnet/VLAN, and the switch ports have no errors. I'm going
to set up a span capture but does anyone have any suggestions on where
to look? CUCM 10.5.2.15900-8, 7975/7965 with SCCP[47]5.9-4-2SR2-2S.

Parameter 	Origination 	Destination
MediaTransportAdd_Ip 	10.100.254.227 	10.100.253.223
PayLoadCapability 	6 	6
MediaCap_g723BitRate 	0 	0
Packets Sent 	714 	712
Octets Sent 	122808 	122464
Packets Received 	711 	0
Octets Received 	122292 	0
Packets Lost 	0 	0
Jitter 	0 	0
Latency 	0 	0
QoS 	G 	G
VideoCap_Codec 	0 	0
VideoCap_Bandwidth 	0 	0
VideoCap_Resolution 	0 	0
VideoTransportAddress_IP 	0.0.0.0 	0.0.0.0
VideoTransportAddress_Port 	0 	0
 --
James Andrewartha
Network & Projects Engineer
Christ Church Grammar School
Claremont, Western Australia
Ph. (08) 9442 1757
Mob. 0424 160 877