IP Office Troubleshooting
VoIP Calls Not Tagged with Priority over Data Packets
VoIP calls are not tagged with priority over data packets on the LAN network.
For VoIP calls to be routed and treated appropriately on the LAN network, they need to be tagged with the appropriate Quality of Service/DiffServe values and the same values need to be set on the network.
I. Check the tagging values IP Office is assigning to VoIP calls.
1. Log onto Manager and open the IP Office configuration.
2. Click System and double-click the system you are configuring.
3. On the Gatekeeper tab, check the following fields:
• DSCP(Hex): The value entered here defines the Quality of Service/DiffServe setting applied to the VoIP calls. The default value is 0xB8 which equates to a DSCP (DiffServ Code Point) of 46 in decimal format.
• DSCP Mask(Hex): The value entered here defines the mask to be applied to the packets for the DSCP value. The default value is 0xFC with 63 as the equivalent value in decimal format.
4. Check that all routers and switches on the LAN network are set to use the same values to allow for proper routing of VoIP calls.
II. Using a Protocol Analyzer such as Ethereal, Observer or Sniffer. Check that the IP Office is sending data with the appropriate priority header settings as defined above.
III. If the problem persists after you have performed ALL these troubleshooting steps, gather the following information BEFORE escalating the issue:
• A copy of the IP Office configuration will be useful before escalating to your support organization.
• The username and password of the configuration must be provided to your support organization for testing purposes.
• Any trace codes or log files generated by the System Monitor application (if available).
• Notes relating to the result of each of the verification steps performed above.
• The customer's network diagram (if applicable).
If the priority is set appropriately and the Protocol Analyzer trace shows the priority value and the problem still persists, then the customer's network needs investigating.