Table 9.9 is a quick reference guide to basic troubleshooting steps to try in the event of unsuccessful QoS deployment:
| Symptom |
Suggested Remedy/Investigation |
| No connectivity |
- 802.1p enabled on sender but not on receiver.
- Non-802.1p—capable device between sender and receiver.
- Failed traffic control installation; remove and reinstall QoS Packet Scheduler Service.
- Registry entry MaxOutstandingSends in \Psched\Parameters set too low.
|
| No discernible effect of QoS |
- End-to-end QoS signaling failure or traffic control failure. See "Troubleshooting Methodology" later in this chapter for assistance with tracing the source of the failure.
- Network not congested.
- No active QoS elements in those parts of the network that are congested.
- Packets not tagged correctly with 802.1p.
- Packets not marked correctly with DSCP.
|
| QoS ACS policy ineffective |
- Policy configured in QoS ACS that is not the DSBM on the relevant segment (use the tool Wdsbm to find out which QoS ACS is the DSBM).
- Verify that the QoS ACS is running under the account name of QoS ACSService. See Windows 2000 Server Help for procedural information.
|
| RSVP messages dropped in the network |
- Router in path dropping RSVP messages. Use Rsping to verify integrity of RSVP path.
- RSVP messages dropped due to congestion; verify 802.1p and DSCP marking for RSVP network control flow.
|
| RSVP reservation requests rejected |
- Insufficient resources provisioned in intervening routers or QoS ACS.
- Policy denial by QoS ACS.
|
| Packets not tagged 802.1p |
- Traffic control not installed.
- 802.1p not enabled on interface.
- QoS request denied for traffic flow.
- Non-802.1p-capable interface.
|
| Packets tagged with unexpected 802.1p tag |
- This is being overridden by a registry setting by the administrator.
- TCLASS override in effect.
- Packets nonconforming.
|
| Packets marked with unexpected DSCP |
- Registry override in effect.
- DCLASS override in effect.
|
