If a link does not come into service shortly after downloading the configuration files to the board, determine the cause of the problem from the txalarm messages. Physical connection problems are the primary cause of link initialization failures, and are usually indicated by a repeated sequence of alarms, as shown in the following example:
<06/04/08 11:04:26> mtp 1 16387 Layer1: SUERM Threshold Reached (Lnk 0)
<06/04/08 11:04:26> mtp 1 16387 LinkFailure : was in service (Lnk 0)
<06/04/08 11:04:26> mtp 1 16387 Sent SIOS (Lnk 0) (Fail in InService)
<06/04/08 11:04:26> mtp 1 18228 MTP3 Pause for DPC 1.1.2 (0x10102), OPC 1.1.1 (0x10101)
<06/04/08 11:04:27> mtp 1 16387 Flushing Buffers (OutPktCnt=0) (Lnk 0)
<06/04/08 11:04:27> mtp 1 18180 MTP3 Link 0 Down
<06/04/08 11:04:27> mtp 1 16387 Flushing Buffers (OutPktCnt=0) (Lnk 0)
<06/04/08 11:04:27> mtp 1 16387 Starting Alignment (Lnk 0)
<06/04/08 11:04:27> mtp 1 16387 Sent SIO (Lnk 0)
<06/04/08 11:04:39> mtp 1 16387 ALIGN TIMER 2 EXPIRED iacSt=8 (Lnk 0)
<06/04/08 11:04:39> mtp 1 16387 LinkFailure (Lnk 0): Alignment Not Possible
<06/04/08 11:04:39> mtp 1 16387 Sent SIOS (Lnk 0) (AlignNP in InitialAlign)
<06/04/08 11:04:40> mtp 1 18180 MTP3 Link 0 Down
Some of the causes of physical link connection problems are:
Missing or loose cable connections between the T1/E1 ports.
Missing bus cable when one board is deriving clocking from the H.100/H.110 bus.
Incorrect clocking configuration between the two boards (for example, both boards driving H.100/H.110 bus clocks, neither driving H.100/H.110 bus clocks, clocking not synchronized to T1/E1 port).
Mismatched channel timeslot assignments between the two boards.
The link can also align successfully at layer 2 but fail the signaling link test at layer 3, resulting in this type of alarm:
<06/04/08 11:05:04> mtp 1 16387 Rcvd SIOS (Lnk 0)
<06/04/08 11:05:04> mtp 1 16387 Rcvd SIO (Lnk 0)
<06/04/08 11:05:04> mtp 1 16387 Sent SIE (Lnk 0)
<06/04/08 11:05:04> mtp 1 16387 Rcvd SIO (Lnk 0)
<06/04/08 11:05:04> mtp 1 16387 Rcvd SIE (Lnk 0)
<06/04/08 11:05:05> mtp 1 16387 Timer 4 Expired (LINK 0 ALIGNED at layer 2)
<06/04/08 11:05:05> mtp 1 16387 MTP3: Link 0 SNT msg dropped, bad point code (1.1.3 (0x10103))
<06/04/08 11:05:05> mtp 1 16387 MTP3: Link 0 SNT msg dropped, bad point code (1.1.3 (0x10103))
<06/04/08 11:05:05> mtp 1 16387 MTP3: Link 0 SNT msg dropped, bad point code (1.1.3 (0x10103))
<06/04/08 11:05:05> mtp 1 16387 Deactivating link 0 due to MaxSLTRetries!
This type of failure is almost always caused by one of the following configuration errors:
Point codes assigned to each of the boards in the MTP 3 configuration file do not properly refer to each other.
Link select code assigned to the link in the MTP 3 configuration file (LINK_SLC) of one board does not exactly match the link select code assigned to the same link in the MTP 3 configuration file of the second board.