Slot 1 ISDN Interface 2 : Link activation lost or not achieved.
Slot 1 ISDN Interface 2 : Link activation achieved.

- the ISDN line on Port 2 has dropped
- move the ISDN line to another port (configure that port with the matching ISDN configuration) then see if the problem follows the line. If so check with your Telco on line problems, otherwise there may be a problem with the Port.

Slot 1 ISDN Interface 1 : No response from ISDN provider to TEI assignment/verification request.

- check with the Telco and verify that the ISDN configuration matches the Perle's configuration. Most likely cause is a mismatch in the ISDN Network Protocol.

Slot 1 ISDN Interface 1 : SPID not accepted by ISDN provider.

- verify that the SPID configured in the Perle's configuration matches the Telco's ISDN subscription for that specific line (also verify the ISDN Network Protocol).

41000000 (S1I2C1 CDN failure)

- the Channel Directory Number (CDN) configured on the line does not match the Directory Number given by the Telco. Verify the DN number with the Telco. Note: if a Hunt Group was configured by the Telco then the DN may be setup as one number for ALL channels.

Resource event log: S1CH01 S1M04 : freed from port 9 (0-00010003)
Resource event log: S1CH01 S1M04 : allocated to port 9 (DI-6029384562)

- a call has been answered by the Perle and has failed to negotiate PPP.
- As there is no "Logon" message this would indicate that the call failed due to the Perle not being able to communicate to the Authentication server.

41011001 (S1M07 Modem Disconnect Reason 41-23)

- call was disconnected. See table below for most common reasons:

1 - 21	reason could not be determined
20 - 15	DTR dropped/lost
41 - 23	modem training failed

Disconnects can occur if there are disruptions to the circuit due to excessive line noise (usually on the client's analog Telco circuit) that cause training to fail, PPP negotiation to timeout or drop the connection.

Note: if the Directory Number is mismatched the Perle does not record an Event. The Perle will not answer a call if the Directory Number presented in the setup message delivered by the Telco does not match the Directory Number configured in the Perle.

If Debug level is enabled in the Event Log options then there may be messages that are displayed for Perle Technical Support debugging. These are not necessarily errors.