Subject: SONET APS Question

From: "Nakum, Vimal" <[email-masked]>
Date: Sat, 8 Jun 2002 10:49:36 -0700

Hi, 

In Telcordia standards, it is mentioned that K1/K2 bytes carry APS Protocol
bytes on protection line when signal degrade happens on working line. 

Suppose, we did non-revertive switching from working line to protection line
and traffic starts flowing on protection line. After some time, working line
becomes operational but since it was non-revertive switching, it didn't
switch to working line. But after some time, signal failure happens on the
protection line. Now, in this case, will there be any exchange on K1/K2
bytes on working line, indicating switchover to working line ? Or both ends
automatically switchover to working line ?

Thanks,

Vimal Nakum

---

From: Muly Ilan <[email-masked]>
Date: Mon, 10 Jun 2002 15:02:44 +0200

Vimal,
 
In case of SF on protection line both LTEs should automatically switch back
to the working line.
 
See R5-81, section 5.3.5.5 of GR-CORE-253. Footnote #15 is worth reading "
It is also acceptable for the K1 and K2 bytes in the signals carried on
working lines to carry APS channel information. However, LTE cannot assume
that the APS channel information will be present in the received signal, and
therefore it must be capable of ignoring any APS codes received in those
bytes".

Muly Ilan

-----Original Message-----
From: Nakum, Vimal [mailto:[email-masked]]
Sent: Saturday, June 08, 2002 7:50 PM
To: [email-masked]'
Subject: SONET APS Question

Hi, 

Thanks, 

Vimal Nakum