Cross-Connections for Ethernet
Cross-connections and virtual concatenation
The VLNC50/52/55 Gigabit Ethernet LAN port/VCGs support cross-connection rates of:
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STS-1/VC3 or STS-1/VC3 VCAT (up to 12 STS-1/VC3s)
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STS3c/VC4 or STS-3c/VC4 VCAT (up to 4 STS-3c/VC4s)
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VT1.5/VC12 or VT1.5/VC12 VCAT (up to 63 VT1.5/VC12s)
Each VLNC35 Fast Ethernet LAN port/VCG supports cross-connection rates of:
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STS-1/VC3 or STS-1/VC3 VCAT (up to 3 STS-1/VC3s)
-
one STS3c/VC4
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VT1.5/VC12 or VT1.5/VC12 VCAT (up to 63 VT1.5/VC12s)
The first cross-connection to the VCG sets the rate for all remaining cross-connections.
Important rules for cross-connections
Ethernet cross-connections tie together VCG tributaries in two or more Ethernet circuit packs through SONET/SDH tributaries. For example, a cross-connection of m1-1-1 to d1-v1-1 at Node A (Alcatel-Lucent 1850 TSS-5), and a cross-connection of m1-1-1 to g1-v1-1 at Node B (Alcatel-Lucent 1665 DMXtend) ties d1-v1-1 (VCG1, tributary 1) at Node A to g1-v1-1 (VCG1, tributary 1) at Node B.
When more than one VCG tributary is being cross-connected to provide an Ethernet service, the order in which the VCG tributaries are connected must be the same at both ends of a span. Tributaries on the SONET/SDH side do not have to be in order, but they do have to align with the VCG tributaries at both ends. See examples below.
For multiple VCG tributary cross-connections, it is strongly suggested that VCG tributary cross-connections begin at VCG tributary #1, then VCG tributary #2, and so forth to the last cross-connection. It is also suggested that the VCG tributary cross-connections be established in an increasing (ascending) order at each end of the span as shown in the example that works.
This example works:
|
NODE A (Alcatel-Lucent 1850 TSS-5) |
NODE B (Alcatel-Lucent 1665 DMXtend) |
|---|---|
|
m1-1-1 <-> d1-v1-1 |
m1-1-1 <-> g1-v1-1 |
|
m1-1-2 <-> d1-v1-2 |
m1-1-2 <-> g1-v1-2 |
|
m1-1-3 <-> d1-v1-3 |
m1-1-3 <-> g1-v1-3 |
This example does not work:
|
NODE A (Alcatel-Lucent 1850 TSS-5) |
NODE B (Alcatel-Lucent 1665 DMXtend) |
|---|---|
|
m1-1-1 <-> d1-v1-1 |
m1-1-1 <-> g1-v1-3 |
|
m1-1-2 <-> d1-v1-2 |
m1-1-2 <-> g1-v1-2 |
|
m1-1-3 <-> d1-v1-3 |
m1-1-3 <-> g1-v1-1 |
Cross-connection types
Alcatel-Lucent 1850 TSS-5 supports the following cross-connection types for Ethernet services:
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UPSR/SNCP Ring Add/Drop: A two-way cross-connection between a tributary on a UPSR/SNCP protected interface and a tributary on a VCG port in function group C or D.
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1+1 Add/Drop: A two-way cross-connection between a tributary on a 1+1 protected interface and a tributary on a VCG port in function group C or D.
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2-Way Point-to-Point, Through: A two-way cross-connection between the two sides of a UPSR/SNCP node. Traffic received on a timeslot on one side of the UPSR/SNCP node is passed through to the same timeslot on the opposite side of the UPSR/SNCP node.
-
Linear/Unprotected UPSR/SNCP: A two-way cross-connection between a tributary on one side of an UPSR/SNCP interface and a tributary on a VCG port in function group C or D.
-
2-Way 0x1 Add/Drop: A two-way cross-connection between a ring channel on a main port which has an application value of 0x1 to another main port, which has the application value 0x1/UPSR/SNCP, or to a VCG port in function group C or D.
Figure 11-1, UPSR/SNCP Ring Add/Drop cross-connection example shows a UPSR/SNCP Ring Add/Drop cross-connection between an STS-1/VC-3 tributary in an OC-n/STM-n interface and an Ethernet VCG port on the VLNC50/52/55 circuit pack.
Figure 11-1: UPSR/SNCP Ring Add/Drop cross-connection example
Figure 11-2, 2-Way Point-to-Point, Through cross-connection example shows a 2-Way Point-to-Point, Through cross-connection between the STS-1/VC-3 tributaries of an OC-n/STM-n interface on a VLNC50/52/55 circuit pack.
Figure 11-2: 2-Way Point-to-Point, Through cross-connection example
Figure 11-3, Linear/Unprotected UPSR/SNCP cross-connection example shows a Linear/Unprotected UPSR/SNCP cross-connection between an STS-1/VC-3 tributary on one side of a UPSR/SNCP interface and an Ethernet VCG port on the VLNC50/52/55 circuit pack.
Figure 11-3: Linear/Unprotected UPSR/SNCP cross-connection example
Figure 11-4, 2-way 0X1 Add/Drop cross-connection example shows a 2-way 0x1 Add/Drop cross-connection between an STS-1/VC-3 tributary in an unprotected OC-n/STM-n interface and an Ethernet VCG port on the VLNC50/52/55 circuit pack. .
Figure 11-4: 2-way 0X1 Add/Drop cross-connection example
