Table of Contents
Advertisement
Chapter 11
Circuits and Tunnels
Table 11-11
Hex Code
0xEA
0xEB
0xEC
0xED
0xEE
0xEF
0xF0
0xF1
0xF2
0xF3
0xF4
0xF5
0xF6
0xF7
0xF8
0xF9
0xFA
0xFB
0xFC
0xFF
11.15 Automatic Circuit Routing
If you select automatic routing during circuit creation, CTC routes the circuit by dividing the entire
circuit route into segments based on protection domains. For unprotected segments of circuits
provisioned as fully protected, CTC finds an alternate route to protect the segment, creating a virtual path
protection configuration. Each segment of a circuit path is a separate protection domain. Each protection
domain is protected in a specific protection scheme including card protection (1+1, 1:1, etc.) or SONET
topology (path protection, BLSR, etc.).
The following list provides principles and characteristics of automatic circuit routing:
•
•
78-18106-01
STS Path Signal Label Assignments for Signals with Payload Defects (continued)
Content of the STS SPE
STS-1 with 10 VTx PDs
STS-1 with 11 VTx PDs
STS-1 with 12 VTx PDs
STS-1 with 13 VTx PDs
STS-1 with 14 VTx PDs
STS-1 with 15 VTx PDs
STS-1 with 16 VTx PDs
STS-1 with 17 VTx PDs
STS-1 with 18 VTx PDs
STS-1 with 19 VTx PDs
STS-1 with 20 VTx PDs
STS-1 with 21 VTx PDs
STS-1 with 22 VTx PDs
STS-1 with 23 VTx PDs
STS-1 with 24 VTx PDs
STS-1 with 25 VTx PDs
STS-1 with 26 VTx PDs
STS-1 with 27 VTx PDs
VT-structured STS-1 SPE with 28 VT1.5
(Payload defects or a non-VT-structured STS-1 or STS-Nc SPE with a payload
defect.)
Reserved
Circuit routing tries to use the shortest path within the user-specified or network-specified
constraints. VT tunnels are preferable for VT circuits because VT tunnels are considered shortcuts
when CTC calculates a circuit path in path-protected mesh networks.
If you do not choose Fully Path Protected during circuit creation, circuits can still contain protected
segments. Because circuit routing always selects the shortest path, one or more links and/or
segments can have some protection. CTC does not look at link protection while computing a path
for unprotected circuits.
11.15 Automatic Circuit Routing
Cisco ONS 15454 Reference Manual, R8.5
11-27
Advertisement
Table of Contents
