Ethernet Circuit/XCVT Limitations?

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May 22nd, 2008
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We are running a 20 node, ONS-15454 SONET ring, OC-48, with XCVT and the E100T-12-G Ethernet cards in each node.

One node currently has 3) STS-1 Ethernet circuits provisioned to it and we wanted to add 4)new STS-3c circuits. The first two were created with no problem but when the 3rd was being created, the option to select the Ethernet card slot was no longer available, only the OC-48 cards. We are able to create 3 new STS-1 circuits, with no problems, but no STS-3c.

Are we simply maxing out our cross-connect/XCVT? Is there some limitation on the E100T-12-G cards? Will upgrading to the XC10G remedy the problem?

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tphelps Thu, 05/22/2008 - 13:22
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1. What software release are you running?

2. Is the card in EtherSwitch mode or Stitched/Group mode?

3. Is there SPR?

4. Are you in port mapped mode?

You typically get up to STS-12c of bandwidth to an E-series card. 3x STS-1 and 4x STS-3c is more than STS-12c. Also, creating the larger circuits (STS-3c) first then smaller (STS-1) circuits may be required.

I doubt the XC is maxed out if the only ring is OC-48.

Tom Randstrom Thu, 05/22/2008 - 15:08
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As a follow-on to "tphelps" comments, the E-Series card's bandwidth is limited to a maximum of STS-12 to the backplane. As was earlier stated, restrictions required circuits to be created in a specific order, per the notice url provided below (I would assume the restrictions are still valid in newer SW).

Depending on the type of Ethernet circuits you are trying to carry across the optical network (pt-to-pt, shared packet ring), you may want to consider using the newer CE-series, G-Series or ML-series Ethernet cards. The E-Series cards are of an old design and have been EoL'd.

Hope this helps.

Tom Randstrom Tue, 06/17/2008 - 18:07
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Correct. The STS-1s need to be contiguous for an STS-3c circuit. If only the card supported virtual concatenation (which it does not), then any 3 STS-1s could be used to create a virtual STS-3c.


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