Dual Ring Capabilty for ONS 15454 MSTP

[hashaari]

Hi!

I am designing a MPLS over DWDM network which consist of one core DWDM ring and several regional DWDM ring using ONS 15454 MSTP. I would like to connect the regional ring to the core ring via P router in this case Cisco 12406GSR. My major concern now is to reduce the number of boxes especially on the DWDM part. Can an ONS box connect to 2 DWDM ring, regional and core directly without using a router in the middle. Apreciate your expert opinions. Thanks.

Rgds

Helme

[Marvin Rhoads]

Sure, 15454 MSTP's can accomodate multiple rings. You just provison circuits (T-1, DS-3, OC-x, etc.) between them.

From the product overview publication: "UPSRs and BLSRs can be subtended from one another using one shared node; the node can terminate and groom any one of the following ring combinations:

? 5 UPSRs, or

? 4 UPSRs and 1 BLSR, or

? 3 UPSRs and 2 BLSRs

Subtending rings from a ONS 15454 reduces the number of nodes and cards required, and reduces external shelf-to-shelf cabling."

[hashaari]

Hi!

Ok that's good. How exactly can this be done, I mean what card to use, how it is connected and how traffic is passed between the rings. For example say the core DWDM ring consist of 4 node A,B, C and D and regional ring consist of 3 node E, F and G. I want to interconnect the ring at D. Appreciate your expert opinions.

[Marvin Rhoads]

In your example, node d has to be part of both rings. It could have, at it's simplest, a pair of optical cards (along with its TCC and, if you are crossconnecting circuits internally, the XC card). You provision card #1 as part of your core DWDM ring and card #2 as part of your regional ring. It participates in DCC signalling on both rings. When you build circuits in CTC, the XC card in node D will allow you to groom off of one ring and onto the other.

Alternatively, you could "drop" circuits from one ring and "add" them onto the other via optical or electrical physical cross connects at node D.

[rtappend_2]

Core DWDM ring and Regional DWDM ring are built using ROADM cards for full add/drop flexibility. Wavelengths can be engineered to pass between rings by physically patching at the wavelength level. By using the Mesh/Multiring Upgrade card (available today - see data sheet below) you can prepare the network for Degree-N capability, allowing multiple rings to be connected via a single point with dynamic wavelength provisioning across the rings.

http://www.cisco.com/en/US/products/hw/optical/ps2006/products_data_sheet0900aecd803fc502.html