RE: Question about SONET Transparency

[Heiles Juergen <Juergen.Heiles@icn.siemens.de>]

David,

you get section/regenerator transparency when you transport the SONET/SDH signal over an DWDM network (either pure wavelength or ODU/digital wrapper) without any termination of the SONET/SDH overhead. Line/Multiplex section transparency is achieved when you transport the SONET/SDH signal over a DWDM system (either pure wavelength or ODU/digital wrapper) that terminates the section/regenerator overhead. The later is for example the case if the transponder/wavelength converter has SONET/SDH regenerator functionality.

Regards

Juergen

> -----Original Message-----
> From: David Wang [mailto:david.wang@metro-optix.com]
> Sent: Wednesday, April 24, 2002 6:15 PM
> To: 'ccamp@ops.ietf.org'
> Cc: Todor Markov; Steven D. Sensel
> Subject: Question about SONET Transparency
> 
> 
> [ post by non-subscriber ]
> 
> Dear Experts,
> 
> In draft document "GMPLS extension for SONET and SDH 
> Control",  one of the
> SONET/SDH parameter is the "Transparency" field. Two values 
> has been defined
> for this field. 
> 
> Flag 1 (bit 1): section/regenerator transparency, which means 
> all overhead
> bytes will be unchanged in the intermediate device.
> Flag 1 (bit 2): Line/multiplex transparency, which means 
> LOH/MSON cannot be
> changed in the intermediate device.
> 
> By definition, in SONET network the SOH will be read and 
> re-written at the
> end of each section span and LOH will be read and re-written 
> at the end of
> each line span. Where this "transparency" come from? Is it for Digital
> Wrapper? Can somebody give me some background information or 
> point to me
> some Bell Core or ITU-T document or some technical document I 
> can find the
> answer to this "Transparency" SONET/SDH.
> 
> Thanks very much
> David
> 
>