Description of the problem

An OSN 3500 device with an expansion subrack exists in the current network, and the expansion subrack is configured with ssn1pq1 logical single boards in slots 52, 53, 54, 55, and 63, and ssn1pd3 logical single boards in slots 64, 65, and 66. When the customer creates a 66-18-1:20:1 VC3 bidirectional service there is an error reported with an error code of 38882, i.e., insufficient low-order crossover resources.

Processing

1. Confirm whether the remaining cross capacity of the cross single board is sufficient.

Query the remaining cross-capacity of the cross-single board, and there is still a lot of remaining capacity. It is sufficient to support the capacity required for the configuration service.

:cfg-get-lowxc-capacity:9;.

LOW-XC-CAPACITY

BID MAX-CAPACITY MAX-VC4-NUM LEFT-SRC-VC4-NUM LEFT-DST-VC4-NUM LEFT-DST-VC12-NUM LEFT-DST-VC3-NUM

9 40 256 205 205 13713 630

Total records :1

2. The configuration service involves the expansion subrack single board, and the capacity of the expansion subrack cross single board XCE is small (8 VC4, 1.25G), so it is suspected that the capacity of XCE is insufficient.

The cross-matrix configuration of this network element is filtered and screened to the extended subrack single board as the host service. It can be known that there exist VC12 services in slots 52, 53, and 55, and the 52, 53, and 55 veneer types are ssn1pq1, so they occupy 3 VC4s.

Putting the cross-matrix configuration of this network element into filtering and screening, you can know that there exist VC3 services in slots 64 (1, 4, 5, 6VC3) and 55 (1, 4, 5, 6VC3). And 52, 53, 55 veneer type is ssn1pd3, then it occupies 4 VC4.

Note: PD3 veneer boards 1, 2, and 3 VC3 occupy one VC4, and 4, 5, and 6 VC3 occupy one VC4.

At the same time, there exists an SNCP service on this network element that is hosted on veneer 54, and veneer 54 type is ssn1pq1, then it occupies one VC4.

:cfg-get-sncpbdmap:2;.

SNCP-PU-MAP

PG-ID PU-ID SRC-BID SRC-PID SRC-AU4 SRC-PATH DST-BID DST-PID DST-AU4 DST-PATH XC-LEVEL

2 work 3 1 1 13 54 13 0 0 vc12

2 backup 3 2 1 13 54 13 0 0 vc12

Through the above analysis, you can know that the services configured to the expansion subrack occupy a total of 8 VC4s, and the XCE supports a maximum of 8 VC4s. Among the services currently occupying VC4s, there is no service that uses the 66th board as a source or a host. So no new VC4 can be assigned to slot 66. then error 38882 is reported.

3. expand Subrack Low-order Services Crosscutting Knowledge Points.

The XCE board in the extended subrack does not support low-order service time-division crossover. the low-price services on the extended subrack are completed in the XCS board on the main subrack for low-order service time-division crossover. the XCE board completes only a VC4 null-division crossover in a certain slot to the first several VC4s in the cables of the extended subrack. the following scenario occurs due to the XCE crossover capacity of 8 VC4s (1.25G):

a. When the expansion subrack veneers are all PQ1/PQM/PL3 veneers and the XCS veneers have sufficient low-cost capacity. you can configure the service of any veneer.

b, When the expansion subrack veneer boards are all PD3 veneer boards or PD3 veneer boards are mixed with PQ1/PQM/PL3 veneer boards, and the XCS veneer boards have sufficient low-price capacity, you can configure a maximum of 8 VC4 services (please note that not all the low-order services sum up to 8 VC4s).

Root Cause

The XCE cross-single board supports a maximum of 8 VC4s (1.25G), and when the service configured in the expansion slot occupies more than 8 VC4s, an error is reported.

Solution

Please check whether it is possible to optimize the redundant VC4 according to the current network configuration, and if so, please carry out business optimization.

Suggestion and Summary

None

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