Thank you in advance for any help you can offer. I have been troubleshooting voice quality on a new IPO 500V2 8.0.42 installation and am currently stumped.
The installation consists of approximately 58 IP extensions; 9650, 1603, and 3725 DECT phones. The IP Telephones are on a dedicated (physically separate) PoE data infrastructure. LAN 1 of the IP Office serves as DHCP server and is connected to the PoE switch stack, LAN 2 is on the customer data network and connected to the data switch stack. There is no connection between the VoIP and Data network (I have checked the MAC tables in the VoIP switches) except through the IP Office.
I have been getting QoS Voice Quality alarms and degraded voice for several weeks now. A reset of the IP office and/or switch stack seems to improve the situation for a period of time, but the quality soon degrades again. I have tested the following:
1) Verified spanning tree and root bridge configuration is the primary switch, verified that no switching loops were detected. Physically inspected cables to verify no broadcast storm.
2) Viewed statistics in the switches to verify that most traffic is unicast, and that there are not broadcast storms or errored packets.
3) Mirrored the LAN1 port on the IP Office and collected flow statistics using a diagnostic appliance. This revealed some interesting and seemingly inexplicable information:
* Several of the RTP ports 49152, 49154, 49158, etc seemed to remain open and continue to generate traffic roughly equivalent to a g.711 media stream despite all devices in the system being idle (even at 2 am on a sunday).
* This behaviour cleared somewhat when the IPO was rebooted, but quickly re-established itself after a few hours in service.
* I reset the entire switch stack and IP office, and the behaviour seems to have cleared (for the last few hours)
4) Tried to run a VoIP assesment against the installed VoIP terminals. I get a 90% packet loss to ICMP pings to all of the 9650 and 1603 terminals but not to the DECT repeaters or IPO LAN1 port...
* are the phones designed to ignore ICMP? Or is this a hint?
The installation consists of approximately 58 IP extensions; 9650, 1603, and 3725 DECT phones. The IP Telephones are on a dedicated (physically separate) PoE data infrastructure. LAN 1 of the IP Office serves as DHCP server and is connected to the PoE switch stack, LAN 2 is on the customer data network and connected to the data switch stack. There is no connection between the VoIP and Data network (I have checked the MAC tables in the VoIP switches) except through the IP Office.
I have been getting QoS Voice Quality alarms and degraded voice for several weeks now. A reset of the IP office and/or switch stack seems to improve the situation for a period of time, but the quality soon degrades again. I have tested the following:
1) Verified spanning tree and root bridge configuration is the primary switch, verified that no switching loops were detected. Physically inspected cables to verify no broadcast storm.
2) Viewed statistics in the switches to verify that most traffic is unicast, and that there are not broadcast storms or errored packets.
3) Mirrored the LAN1 port on the IP Office and collected flow statistics using a diagnostic appliance. This revealed some interesting and seemingly inexplicable information:
* Several of the RTP ports 49152, 49154, 49158, etc seemed to remain open and continue to generate traffic roughly equivalent to a g.711 media stream despite all devices in the system being idle (even at 2 am on a sunday).
* This behaviour cleared somewhat when the IPO was rebooted, but quickly re-established itself after a few hours in service.
* I reset the entire switch stack and IP office, and the behaviour seems to have cleared (for the last few hours)
4) Tried to run a VoIP assesment against the installed VoIP terminals. I get a 90% packet loss to ICMP pings to all of the 9650 and 1603 terminals but not to the DECT repeaters or IPO LAN1 port...
* are the phones designed to ignore ICMP? Or is this a hint?
