Guest

Cisco ONS 15800 Series DWDM Platforms

Field Notice: FN - 61110 - ONS15808 - The LASEROFF Command Should Be Avoided


Revised September 28, 2005

September 11, 2002


NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Products Affected

Product

Comments

15808-TT-25G-Cxx

Line Transponder - 2.5 Gbps - C band - Channel 01-80

15808-LT-25G-Cxx

Line Transponder - 2.5 Gbps - C band - Channel 01-80

Problem Description

After sending LASEROFF OFF and LASEROFF ON commands, in sequence, either through local craft or through TL1 interface on Transmit Transponder units listed above, the next receiver in the route starts detecting B1 and B2 errors.

Background

During LASEROFF OFF status the Modulator is not switched Off and so the relative Vbias working point can drift. This misbehaviour causes that after LASEROFF ON command the Modulator works on a wrong working point and thus the errors.

Problem Symptoms

A Receiver in a route detects B1 and B2 errors after switching Off and then On the previous TT/LT laser.

Workaround/Solution

The suggested solution is to switch the laser On and then perform a hardware reset on the unit. Extracting and re-inserting the unit will accomplish this.

It is strongly suggested to avoid using the LASEROFF OFF command. To get the unit to show the same behavior (in case some tests require it) it is possible to disconnect the input signal fiber.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

DDTS

Description

CSCuk36903 (registered customers only)

TT25G: laser off condition cause modulator drift

CSCuk36921 (registered customers only)

LT25G: laser off condition cause modulator drift

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:

Receive Email Notification For New Field Notices

Product Alert Tool - Set up a profile to receive email updates about reliability, safety, network security, and end-of-sale issues for the Cisco products you specify.