ONS 15540 ESPx splitter protection and deployment

[hashaari]

Hi!

Got a question on splitter protection mechanisims on ONS 15540 ESPX. I understand that to implement this kind of protection requires a transponder module to be connected to a splitter base LCMB which then connect to the OADM of the same channel/band group that goes east and west. So does the splitter mechanisims on ONS 15540 ESPx works like the one on ONS 15252 which split in ratios like 10/90, 50/50 etc?

On DWDM deployment, specifically for ONS 15540 ESPX, We planned ultimately to deploy at four sites, say A B C and D in ring topology. My problems is that site C couldn't be ready in time due to construction delays. Is it technically possible to deploy site A B and D first and then break the ring later to deploy site C between B and D? Is there any impact on channel planning, optical power budget and how should I go on implementing the 3 sites first. On first look, I don't think they are no problems as it is just a matter of add/drop/passthru of channels.

Thanks in advance for your help!

[beth-martin]

I am not sure about the impacts. You could however take a look at this page. It contains planning and design guides which would be of help.

http://cisco.com/en/US/products/hw/optical/ps2011/products_implementation_design_guides_list.html

[rtappend_2]

The splitter mechanism on the ONS15540 operates in fixed 50/50 ratio only.

You are right, it is technically feasible to add a 4th site to an existing 3 node ring. The considerations could include:

- Optical Budget (Fibre) - will the fibre initially be routed into Site C and patched through? or will it run directly past the site. If the fibre must be respliced/patched into the new site, this will involve additional fibre losses as well as extra outage time while they perform this work once the site is ready.

- Optical Budget (System) - the ONS15540 at site C will introduce OADM pass-thru losses to existing channels traversing the link between B and D. These may include channels also from A-B and A-D as well as B-D, depending on protection requirements. You should consider this impact from the outset and determine if budgets are within range, or if amplification is necessary.

- Amplification - is there any amplification in this network? If so, the addition of extra channels will change the aggregate power levels and may require some tuning to avoid saturating your EDFAs.

- Impact of upgrade - if channels are protected, you can switch them to the non-affected path while you perform the upgrade. If not, those services will be out of action during the upgrade.

I think the main thing is consider the before and after optical budgets now to make sure there are no surprises in store.

Hope that helps.

[hashaari]

Hi!

So the key here is the impact on optical power budget right? Got it. Thanks for the help.