Ethernet over WDM and SDH

[gaurav_saxena]

How do we manage ethernet circuits over WDM and SDH transmission network? What all OAM tools are available for managing and diasnosis of these circuits.

[Marvin Rhoads]

Ther are several diffent methodologies for transmission of Ethernet over WDM and SONET. The two most common ones that come to mind are Packet over Sonet (PoS) and G.709 encapsulation (over WDM). Neither lends itself well to integration with the native Ethernet tools you may be familiar with. the protocol break typically means a disconnect between any signalling at those respective layers. However, the transport protocols (PoS and G.709) have their own diagnostic tools and error reporting that is presented via their respective interfaces. SONET is a bit more mature in that respect, given it's long history.

Hope this helps. Please rate helpful posts.

[gaurav_saxena]

Hi,

Thanks for your response.My queries here is for Gigabit Ethernet carried over WDM and same way Gigabit Ethernet carried over SDH using GFP encapsulation.Now in both the cases we can use layer one diagnostic available for SDH and WDM. My question is support available at ethernet layer. Since end ports are ethernet ports, these links should support all the ethernet OAM standards like IEEE 802.3ah and IEEE 802.1ag? Can you please let me know which cisco (transmission layer) product support this features?

[nitinkhan]

Gaurav,

ONS 15454 series Sonet/SDH MSPP and MSTP, and 152& 3xx DWDM product line.

When it comes to ONS 15454 product line, ML and G1K series cards provide the FE/GigE services.

[Marvin Rhoads]

I don't believe any of the ONS products have 802.3ag or 802.3ah support. The Catalyst 6500, 4500 and some GBICs have 802.3ah support built into their optical signalling support.

See the white paper "Understanding Intelligent Carrier Ethernet" at http://www.cisco.com/en/US/tech/tk389/tk214/technologies_white_paper09186a00801cd8e1.shtml

for an overview of Cisco's thoughts in this arena.

[udunuwara]

EoSDH is the term used for transporting ethernet frames over a SDH transmission network.If you can remember SDH, one way this can be achieved is using Virtual Concatanation. Here, n x VC12s are concatanated to get the required speed. ex: if n=5, the speed is 10Mbps.(VC12=2Mbps).(i.e Ethernet frames are put inside the VC12 container and transported.)The SDH equipment will give the customer a normal RJ45 Ethernet interface and in the back end, the no. of VC12s corresponding to the Ethernet speed is concataneted and transported over a STM-1/4/16/64. On the other side, the concatnated VC12s are identified and the Ethernet farmes inside the VC12s are mapped on to the Ethernet interface.

If you see the end to end circuit, you will see ethernet. so normal tools used for Ethernet troubleshooting can be used. SDH troubleshooting tools can be used to test the transport part. There may be tools which can troubleshoot moare than this.

[gaurav_saxena]

This is well known fact that carrier class ethernet (EoSDH and EoWDM)is not rich in terms of OAM and fault management features.Lots of work is happening in developing standard ethernet OAM like IEEE 802.1ag and 802.3ah.

My question here is as carrier class ethernet is carried over SDH or WDM layer and SDH and WDM layers are rich in terms of OAM and fault management features, what is the requirement to develop new standards for carrier ethernet OAM, while we can use layer 1 OAM features of SDH and WDM.

As i understand in case of EoSDH, we can troubleshoot on VC level in a VCAT group which is mapped to ethernet frames.

[afriasge]

Hi Gaurav,

Do you have success in this query? I am looking the same information:

SDH, DWDM, carrier ethernet support for OAM (802.3ah) and CFM (802.3 ag)

Thanks in advanced

[afriasge]

For OAM functionality, a Data Communication Channel (DCC) exists over SONET/SDH as well. It can also be used for remote provisioning over a SONET link. This is somewhat similar to Ethernet LMI (E-LMI) and other OAM protocols add to Ethernet to support service provider operations.

DWDM

An optical supervisor channel (OSC) can also be transmitted over the same optical medium to serve OAM purposes; it is analogous to SONET’s DCC.