Common Troubleshooting Issues

Contents:

Initial Configuration

I set the network configuration in the initial configuration page, but I still cannot see the SBC on the network.

• Check the Ethernet port's speed and duplexity and match that to the Ethernet port configuration in the SBC.

After Initial Configuration, I am importing an old backup from a different the SBC, but my T1/E1 ports do not match the configuration.

• Try inserting the card into the other slot. Also, you will have to reset the configuration to factory defaults in order to remove the auto populated ports and restore the old configuration again.

ISDN related issues

• Calling Name is not present on outbound calls over ISDN port with NI2 or Euro-ISDN switch variants
• How to Select User and Network Provided ISDN Calling Number
• ISDN call from PBX to SBC released with cause value -Invalid information element contents 100- by PBX
• MOC conference participants get static when PSTN caller joins the conference

SIP related issues

• Tenor signaling group in SBC is up and then goes down for no apparent reason

Faxing

Where can I find a guide to configure a fax solution for Lync?

• Using a Tenor as an Analog Device in a Lync the SBC SBA Deployment

When do I use G.711 VS T.38?

It is recommended to use G.711 when implementing a fax solution where the SBC Edge (SBC) and the fax server are on the same LAN. T.38 should be used when there are many hops.

The faxes have quality issues

• Check clock source setting.
• Faxes from PSTN via the SBC to FACSys fax server do not complete

• Troubleshooting audio issues in SBC

Audio Quality

• Audio Clipping Issues on Lync - TDM Calls
• One-way audio or call disconnect after call park or hold-transfer to Lync user behind Edge server

Call Completion issues

• Call from PSTN to Lync is rejected by Mediation with SIP message 488 Not Acceptable Here
• Calling number blocking
• Call rejected from PSTN with ISUP cause code 16, the SBC sends 500 Internal Server Error to Lync

Call Presentation

• Calling Name is not present on outbound calls over ISDN port with NI2 or Euro-ISDN switch variants

Certificate Related

• Common Troubleshooting Issues with Certificates in SBC Edge

Lync Deployment

• Config Replication Step of SBA Setup Fails with Failed to run configuration replication script

Lync Operational

• Calls to PSTN numbers fail. Lync declares the gateway unavailable with Event ID 46046
• Lync clients at Branch Site cannot establish MTLS connection with the Central Pool
• Lync Server 2010 Archiving Agent fails to create local queue on the SBA
• When querying Active Directory cache, attributes are missing in the search result
• Workaround for no ring back in PSTN to Lync calls

SNMP

SNMP is not a very efficient method for managing devices.  Excessive polling of the SBC Edge will have an impact on performance: CPU and memory usage increase and the number of calls per second (CPS) will drop.

When managing the SBC, you must consider a balance between the importance of calls and the management data.  If calls are more important, then you want to keep SNMP polls to a minimum and rely on SNMP traps for SBC health.  If management data is more important, just know that it will impact call performance and expect to see increased usage of the CPU and memory.

 For CPS capabilities, refer to SBC Edge Call Performance, located under SBC 1000/2000 Performance and Capacity.