Subject: SONET MIB using for the SDH

From: [email-masked]
Date: Thu, 18 Feb 1999 16:14:31 +0200

Hello,

We have a question about the SONET MIB using for the SDH network.

Example of SDH network has the following managed blocks:
SPI -> RS -> MS -> AU4  -> VC4 -> TU12 -> VC12 -> PDH network.
It can be mapped to SONET MIB by the following way:
SPI, RS, MS are described by ifType = 39 (sonet or sdh), Physical Medium,
Section and Line layers.
AU4 is ifType = 50(sonetPath), sonetPathCurrentWidth = 2.
VC12 is ifType = 51(sonetVT), sonetVTCurrentWidth = 2.

We don't understand, which ifType and CurrentWidth from SONET/SDH MIB can
be used for VC4 and TU12
managed objects.

1.    VC4 can be represented as ifType = 51(sonetVT), but it doesn't have
appropriate value in the sonetVTCurrentWidth.
TU12 can be represented as ifType = 50(sonetPath), but it doesn't have
appropriate value in the sonetPathCurrentWidth.

2.   For SDH, differences between the interfaces with  ifType = 50 and 51
and their CurrentWidth enumerations should be defined more exactly. For
example, TU12 and VC12 are not the same. Note, that both VC4 and TU12
should be managed because they have their specific faults, that can not be
observed in AU4 and VC12 managed objects.

Thanks,

Radion Mirchevsky,

Network Management Group,
Network Systems Department
ECI Telecom Ltd. , Israel , 30 Hasivim St. Petah-Tikva , Israel 49133
e-mail : [email-masked]

---

From: "C. M. Heard/VVNET, Inc." <[email-masked]>
Date: Sun, 21 Feb 1999 09:09:07 -0800 (PST)

On Thu, 18 Feb 1999 16:14:31 +0200 Radion Mirchevsky wrote:

> be used for VC4 and TU12 managed objects.
> [ ... ]
> Note, that both VC4 and TU12 should be managed because they have their
> specific faults, that can not be observed in AU4 and VC12 managed objects.

In the SONET-MIB the AU4 (STS-3c) and the VC4 (STS-3c SPE) are represented
by the *same* ifTable conceptual row.  That is done because these elements
stand in one-to-one correspondence (there is one and only one VC-4
associated with a given AU4 and vice-versa), and there is little to be
gained by having a separate conceptual row for each.  Faults for both
are recorded by the sonetPathCurrentStatus object, which has bits to
represent LOP and AIS defects (which are associated with the AU4) as well
as Unequipped and Path Signal Label Mismatch defects (which are associated
with the VC4).

Likewise, the TU12 (VT-2) and the VC12 (VT-2 SPE) stand in one-to-one
correspondence;  thus, both elements are represented by a common ifTable
conceptual row, and defects for both elements are represented by bits in
the sonetVTCurrentStatus object.

Mike
--
C. M. Heard/VVNET, Inc.
[email-masked]