363-206-285
Technical Specifications
Issue 3 June 2001
10-65
If the default assignments in Table 10-25 do not meet the user’s OS needs,
Releases 8.0, 9.0 and later of DDM-2000 OC-3 allows users to specify the routing
of TL1 autonomous message types to VCs. This is done in two steps:
1. Each TL1 autonomous message type (for example, REPT ALM, REPT
DBCHG, REPT PM, etc.) can be mapped to any OS type (using the ent-
tl1msgmap command at every NE in the subnetwork). The OS types are
tl1Maintenance, tl1MemoryAdministration, tl1test, tl1PeerComm, tl1Other1
and tl1Other2.
2. Each OS type can be mapped to any of the VCs (using the ent-osacmap
command at the TL1 GNE). The combination of Step #1 (mapping TL1
autonomous message types to OS types) and Step #2 (mapping OS types
to VCs) accomplishes the desired mapping of TL1 autonomous message
types to VCs.
At the packet layer, the DDM-2000 OC-3 Multiplexer is configured as a passive
DTE with the following parameters as shown in Table 10-26.
At the link layer, the DDM-2000 OC-3 Multiplexer uses the standard link access
procedure "B" (LAPB) protocol with the following parameters as shown in
Table 10-27.
Table 10-26. TL1/X.25 Interface — X.25 Packet Layer Parameters
Parameter Value
Packet Size
Window Size
D bit support
M bit support
128 bytes
∗
or 256 bytes
2 packets
NO
YES
∗
Release 8.0 (linear), 7.2 (rings) and later
Table 10-27. TL1/X.25 Interface — LAPB Link Layer Parameters
Parameter Value
Maximum Frame Size
Module
Window Size
n2
T1
T3
∗
2104 bits
8
7frames
7 retries
3 seconds
20 seconds
∗
Release 3.2 and later.