Lapd Messages - JDS Uniphase HST-3000 User Manual

Chapter 4 Troubleshooting
Interpreting D channel decode messages
LAPD
messages
108
You can easily determine the source of each message by
looking at the message prefix on the first line. Messages orig-
inating from a TE device begin with TE->NT; messages origi-
nating from a NT device begin with NT->TE. The message in
Figure 24 originated from a TE device.
Each call processed by the D channel is assigned a unique
call reference number, which is reported on the third line of
each decode message. The message in
reference number of 66. All messages exchanged in refer-
ence to the call have the same call reference number. When
viewing decode messages on a D channel processing a
number of calls, it is important to verify the call reference
number for each message because messages for each call
are not presented as a group. A message indicating one call
has been connected may be followed immediately by a
message indicating a different call has been disconnected.
For details on viewing and navigating through D channel
decode messages, see
page 97.
For descriptions of each individual decode message, see
"Services or Supplementary services test results" on
page 150.
LAPD messages are useful when verifying the status of the
D channel link. Complaints prompting you to look at LAPD
messages include:
– The D channel does not go in service.
– D channel communications are lost for no known reason.
– Callers are experiencing excessive delays or timeouts
when trying to place calls.
Using the LAPD messages, you can determine why a
D channel link is not established, if a link is being terminated,
and why a link is being terminated. Three types of frames are
transmitted in LAPD: Information frames, which carry detailed
HST-3000 E1 Testing User's Guide
"Navigating decode messages" on
Figure 24 has a call