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Cisco ONS 15454 Series Multiservice Provisioning Platforms

Field Notice 5: Release 2.0.0 - Deleting VT 1.5 Circuits


April 12, 2000



Products Affected

Product

Comments

Cisco ONS 15454

Formerly Cerent 454

Problem Description

Deleting a Virtual Tributary (VT) 1.5 level circuit or deleting 1+1 protection groups could affect circuits provisioned on slot 1.

The Cerent 454 encapsulates an external signal into a Synchronous Transport Signal (STS) payload on the associated card. Within an STS are 28 VTs. A VT is equivalent to a T1, and an STS is equivalent to OC1. An XC is a Cross Connect card and an XCVT is a Cross Connect with Virtual Tributary capability.

For example, on an DS3-12 card, the card has 12 STS payloads that are fed to the XCVT for routing in the appropriate direction. The DS3s are inserted and extracted from these STS signals on the DS3-12 card.

Background

This problem was discovered during testing in the Cerent System Verification Lab.

Problem Symptoms

The following actions could cause service to be affected on circuits residing on the first STS-1 of slot 1:

  • Deleting any VT 1.5 level circuit

  • Deleting a 1+1 protection group carrying VT 1.5 traffic in the Cerent 454

When in the Circuit Screen, deleting a VT circuit will affect Slot 1 of every node the circuit passes through that has traffic on slot 1, STS 1.

Deleting the 1+1 protection group will affect only the node where the protection group resides. This Field Notice applies to the following modules carrying traffic in slot 1:

  • DS1-14: all ports on slot 1

  • DS3-12: slot 1, port 1

  • DS3XM-6: slot 1, port 1

  • OC-3: slot 1, port 1, STS 1

  • OC-12: slot 1, port 1, STS 1

  • EC1-12: slot 1, port 1

  • E100T-12: Ethernet entire slot

Workaround/Solution

The workaround is to perform software resets on the active and standby XCVT cards for each node that the VT circuit passed through and that has traffic on slot 1.

  1. Log into the Cerent 454 via the Cerent Management System (CMS).

  2. Determine which XCVT is standby.

  3. In the shelf view of CMS, right click over the standby XCVT and choose Reset from the menu.

  4. Allow the XCVT to completely reboot.

  5. Determine which XCVT is active.

  6. In the shelf view of CMS, right click on the active XCVT and choose Reset from the menu.

    caution Caution: This will cause a switch of XCVTs.

    In Cerent Systems you should have redundant Timing Communications and Control (TCC), XC, or XCVT cards so that when you switch you will switch to a standby card and the formerly active card will become standby and be reset.

  7. Allow the XCVT to boot completely (that is, wait until the code is active).

Alternately, the problem can be avoided by not provisioning circuits on slot 1, STS1.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:



Updated: May 28, 2003 Document ID: 22212