[nsp] WS-G5486 and WS-G5487

[Clinton Work]

High latency doesn't sound like an issue with the optical levels on the GigE
circuit. In my experience optical circuits usually fall into one of four states:

a) Rock solid with no stability issues
b) Periodic flapping of the link
c) Degraded state with incrementing interface errors on one or both sides
d) Hard down. 

States a and d are easy to determine.
State c (degraded) circuit can easily be identified by incrementing interface errors.
 The exact details depend upon the platform you are using.

State b (link flaps) can easily be watched by checking the interface or watching for
protocol (OSPF/ISIS/BGP) / interface flaps in the device log (sh log).

Most of the high latency I have seen is caused by link congestion, high cpu, or 
linecard/hardware failures.

Optical pads (Attenuators) aren't designed for just one wavelenght. You can use the
same pad for a 1310nm or 1550nm optical link. I think you are confusing frequency (wavelength)
and power (signal strenght).

In your case you most likely need a pad in the following location:

ZX transmit ---------------------> (5db pad ) --> receive LX 

The size of the optical pad to use (3db, 5db, 10db, 15db) depends upon the distance and
how strong the signal strenght is right before the LX receive. If your having problems
with the link, why don't you just replaced the ZX GBIC with an LX to make both sides
the same?


On Fri, Jun 06, 2003 at 12:14:12PM +0800, Tay Chee Yong wrote:
> Hi Clinton,
> 
> Currently, the circuit is up and running, with one end using a ZX GBIC and the
> other end using a LX GBIC. However, during the peak period we will encounter
> high latency when large packets were send across the link.
> 
> Therefore, I was wondering if its due to this mismatch that causes the high
> latency at night.
> 
> Do you that the end which is using the LX GBIC needs to use a attentuator to
> suppress the frequency generated out from the ZX GBIC?
> 

-- 
=========================================================================
Clinton Work                                        clinton at scripty.com
Calgary, Alberta