Y cable protection 15454 MSTP 9.1

[mladentsvetkov]

Dear all,

Would you please comment the following (in brakets are numbers of sections of the document "Cisco ONS 15454 DWDM Reference Manual, Release 9.1", http://www.cisco.com/en/US/partner/docs/optical/15000r9_1/dwdm/reference/guide/454d91_ref.html):

Issues with Y-cable protection (10.18 Y-Cable and Splitter Protection):

- In a MXP_MR_10DME card provisioned with Y-Cable protection, if a failure is detected on the active path, the traffic is switched to the protect card. In the process of performing the switch operation, the actual end-to-end traffic is affected for up to 15-20 seconds.

- There is a traffic hit of upto a couple hundred milliseconds on the MXP_MR_2.5G and MXP_MR_10DME cards in Y-cable configuration when a fiber cut or SFP failure occurs on one of the client ports.

So does the switchover takes "up to 15-20 seconds" or it takes "couple hundred milliseconds"?

Do you have experience with y-cable protection on "OTU2-XP" cards - how much time it takes for switchover?

Thanks in advance,

Mladen

[Tom Randstrom]

The way I read the statements is the length of the outage will depend on where the outage occurs in the network.

If their is a cable break in the network between the 15454 nodes, then the outage could be 15-20 seconds.

If the failure is between the 15454 card and the client port, then the outage will be a couple of hundred milliseconds.

I do not have experience with the OTU2 cards.

[caoxianglei]

"If their is a cable break in the network between the 15454 nodes, then the outage could be 15-20 seconds. "

Why is the outage so long?

I think for MSPP maybe the MSP or SNCP switchover time is just 50ms. I think when cable break, Y channel device should be detect the Receive Loss, and then switch over in 50ms, why need 15~20s.

I dont understand.

[Tom Randstrom]

Unfortunately, I do not know why.

From my perspective, the switch time should not exceed that of SNCP. Probably a bug they didn't catch in time to correct.