Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Administration and Provisioning
8-14 Issue 3 June 2001
the OC-3 ring. The total traffic handling capacity is determined by the mix of main
to function unit, and function unit to function unit hairpin connections.
OC-1 to OC-1 Hairpin 8
Mapping between OC-1 rings homed onto 27G2-U OLIUs in function unit slots
follows the normal mapping of VTs to OLIUs. The VT tributaries are assigned to
specific STS-1s in the 27G2-U OLIUs. The 27G2-U OLIU has two STS-1s, and
one or two 27G2-U OLIUs are installed in the function unit slots. Two OLIUs are
used for single homing applications, and one OLIU is used for dual homing
applications. Each VT is mapped from one 27G2-U OLIU, with two STS-1s from
which to choose (for example, a-1-1-1, or a-2-1-1) to another 27G2-U OLIU. The
second 27G2-U may be in the same function unit or a different function unit. If it is
in the same function unit, the source and destination STS-1 numbers, which
correspond to the OC-1 lines supported by the 27G2-U OLIU, must be different. If
the second 27G2-U is in a different function unit, note that connections between
the A and the B function units are not allowed.
The traffic handling capacity consumed by the OC-1 to OC-1 hairpin connections
is independent of a shelf’s main to function unit traffic handling capacity. Thus, a
shelf using such connections can connect more than the previous limit of 84
VT1.5s.
The following are examples of OC-1 to OC-1 hairpin VT1.5 time slot cross-
connections:
a-1-1-1 to c-1-1-1 Inter-function unit hairpin
b-2-1-1 to c-1-1-1 Inter-function unit hairpin
a-1-1-1 to a-2-1-1 Intra-function unit hairpin
b-1-1-1 to b-2-2-2 Intra-function unit hairpin
m-1 to c-1
m-2 to c-2
m-3 to c-3
DS3 to EC-1 Hairpin 8
A DS3 signal is mapped to an STS-1 via the asynchronous mapping. The STS-1
is mapped directly to an EC-1 signal.
EC-1 to EC-1 Hairpin 8
An EC-1 signal is converted to an STS-1 signal, which can be connected directly
to another EC-1 signal. If the STS-1 is VT1.5-formatted, connections can be made
between VT1.5 timeslots of the two EC-1 signals.