Cisco ASR SFP-OC3-SR with SFP-OC3-IR1

[salmaan.ozeer]

Hello guys,

I will connect two ASR 1001 using an STM1.

The network is as follows:

I have a first ASR 1001, with SPA-1XOC3-ATM-V2 (STM1 Card) and SFP-OC3-IR1 (SFP module). An STM1 is used to connect another ASR 1001. This time I have an SFP-OC3-SR.

My question is:

The SFP-OC3-SR is compatible with SFP-OC3-IR1 ? or do I need to have SFP-OC3-IR1 on both sides of routers ?

Thanks.

[Iulian Vaideanu]

If you'll be connecting the ASRs over dark fiber then yes, SR and IR1 SFPs are compatible with each other, the only difference between them being loss tolerance:

http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/sonet-sdh-sfp-modules/product_data_sheet0900aecd80285547.html

However, dark fiber availability would allow for much higher bandwidth (using GbE or 10GbE for example), so I'm thinking maybe you'll be connecting the ASRs over some leased capacity, in which case each SFP would have to be compatible with whatever type the carrier is using at each end-point.

[salmaan.ozeer]

Thanks. So the distance specified (in KM) is between the Router and the first switch right?

We only have an STM1 to be able to connect the two routers together..

Can you please tell in which cases the SFP (SR and IR1) won't be compatible ?

[Iulian Vaideanu]

The distance in Km is specified between the router using the SFP and the next device.  If you connect the ASRs through physical fiber, then it will be the length of that fiber path between the ASRs.  If you just lease STM1 capacity through another carrier's network, then it's the fiber distance between your ASR and the carrier's device.

SR and IR1 will always work together (over a reasonable fiber distance, of course).  But if you used leased capacity instead of physical fiber and the carrier used, for example, multimode interfaces, then you may have a problem...

[salmaan.ozeer]

sorry but what do you mean precisely by Leased capacity ? I will just have the STM1 delivered by another carrier..

[Iulian Vaideanu · Accepted solution]

By "leased capacity" I mean STM1 capacity delivered by another carrier on STM1 ports towards your ASR routers and transported from endpoint A to endpoint B through the carrier's active equipment (for example, maybe the carrier has more customers in site A and / or site B, and their STM1 lines are multiplexed with yours over higher-bandwidth links in the carrier's network).

If this is the case, your SFP needs to be compatible with the carrier's STM1 interface in each endpoint.