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RE: what is a "valid SOH"?

HI all

I'm not so sure about that dictionary look-up!

In SONET/SDH world, (as I assume that this concerns, since Moore is talking
about the WIS (WAN Interface Sublayer) assembling 10GE into SONET frames)
the SOH  controls the interaction between regenerator / line sections.

SOH means Section OverHead, (and can be subdivided into a regenerator and a
multiplex SOH).

You need to generate a valid SOH frame (ie. 192 bytes of A1 and A2 and the
other stuff + payload). Whether you want to check them in the RX is your own
choice. I don't think you need to check the  validity of the received SOH,
if you just ensure that you can detect the AIS 



Frank Moore wrote:

  I am working on the AIS-L detection logic of a WIS module. Clause states "The AIS-L functionality implemented by the WIS is
described in and defined fully in Section 7.4.1 of ANSI

ANSI T1.416-1999 states "Line AIS is a STS-N(c) signal containing a
valid SOH with bits 6,7 and 8 of the K2 byte set to 111, and a scrambled
all-ones pattern for the remainder of the signal"

My question is what consistutes a "valid SOH" for a WIS frame. Do I need
to verify 192 A1s followed by 192 A2s or do I just verify that the sync
point happened correctly (ie A1/A2 at byte 192/193). Do I need to verify
that the Z0s are all 0xcc? Do I need to check that all of the unused
bytes are 0x00?

I guess AIS-L doesn't seem so fully defined to me :)

-----Original Message-----
From: Rghines1@xxxxxxx [mailto:Rghines1@xxxxxxx]
Sent: 22. maj 2001 00:40
To: fmoore@xxxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
Subject: Re: what is a "valid SOH"?


SOH: Abbreviation for start-of-heading character.start-of-heading character 
(SOH): A transmission control character used as the first character of a 
message heading.