DS3 Mapping to STM-1

[Vikram Haniyur]

Hi,

I am trying to understand the process of DS3 mapping to STM1.

There seems to be 2 ways of mapping DS3 payload onto STM1.
1. DS3 -> VC-3 -> AU3 -> AUG ->STM1
2. DS3 -> VC-3 -> TU-3 -> TUG-3 -> VC-4 -> AU-4 -> AUG ->STM1

Which is the right way .. or ..are both paths valid ?
What about E3 ? Does it have to follow path #2 ? ( I would guess )

Why would I want to map DS3 to STM1 .. that's another can of worms
altogether.

I would really appreciate any pointers.

Thanks,
-Vikram

[Al]

Vikram

Point (1) below is mapping a DS3 45Mbs (SONET) into an STM1
Point (2) below is mapping a C3 34Mbs (SDH) into an STM1

You would map a DS3 into a STM1 where transport was say from States (SONET)
to Europe (SDH).
In Europe most operators use 45Mb standard as the 34Mb standard wastes
bandwidth except of course where old PDH equipment has only a 34Mb
interface. The 45Mb standard is genrally used for video (Cable operators) as
their Video equipment is from the States and hence it's necessary for SDH
prodcuts to have DS3 compatibility. Blah blah etc etc

Cheers
Al

Vikram Haniyur <vhan...@cisco.com> wrote in message
news:968178374.469774@sj-nntpcache-5...

[Bill Krause]

> I am trying to understand the process of DS3 mapping to STM1.
> There seems to be 2 ways of mapping DS3 payload onto STM1.
> 1. DS3 -> VC-3 -> AU3 -> AUG ->STM1
> 2. DS3 -> VC-3 -> TU-3 -> TUG-3 -> VC-4 -> AU-4 -> AUG ->STM1
> Which is the right way .. or ..are both paths valid ?
> What about E3 ? Does it have to follow path #2 ? ( I would guess )
> Why would I want to map DS3 to STM1 .. that's another can of worms
> altogether.

Both ways above are valid mappings of either DS3 or E3 (using a C-3) in
SDH. See ITU-T G.707 figure 6-1. The choice is dependent on whether
you want the higher-order paths in the STM-1 structured as three
VC-3/AU-3s (compatible with SONET STS-1 SPE) or as one VC-4/AU-4
(compatible with SONET STS-3c SPE only). The recommended multiplexing
for SDH (not SONET) networks is #2 using VC-4/AU-4s. The AU-3 is only
included in the SDH multiplexing structure for SONET compatibility.
Hope to do some design work for Cisco in the future. Call if you need
contract consulting help.

Bill Krause, Sr. Electrical Engineer
Aztek Engineering, Inc., Boulder, CO http://www.aztek-eng.com
"Providing enabling technologies for the telecommunications
access network through custom hardware engineering,
software engineering, and software products".
Aztek Engineering is a leading provider of ETSI V5.1/V5.2, Bellcore
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Aztek has designed telecommunications equipment for numerous
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Aztek has an international reputation for the highest quality
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