How to know if the Optical cable is LC or SC

amb1s1

This is not a test related question. I know that you can check on the cisco website what type of connector you need for certain Card, but I would like to know if there is a command that you can verify on the IOS that tell you what type of optical cable and transceiver that the card is using. Thanks

networker050184

Show interface status will give you what type of SFP is inserted.

ColbyG

amb1s1 wrote: »

This is not a test related question. I know that you can check on the cisco website what type of connector you need for certain Card, but I would like to know if there is a command that you can verify on the IOS that tell you what type of optical cable and transceiver that the card is using. Thanks

You'd have to look up the model of the switch/blade, most likely. Even sh int status will just give you 1000SX or whatever. Old switches use SC or MTRJ, new switches tend to use LC - unless it's a chassis switch, then it's mostly LC for 4500s/Nexus, and SC for 6500s. This varies though.

Trifidw

ColbyG wrote: »

You'd have to look up the model of the switch/blade, most likely. Even sh int status will just give you 1000SX or whatever. Old switches use SC or MTRJ, new switches tend to use LC - unless it's a chassis switch, then it's mostly LC for 4500s/Nexus, and SC for 6500s. This varies though.

I'm not too sure that rule applies to well. The Sup6e in our newer 4500's use X2 modules with SC along with the 10Gb in our 6500's. But you can get twin gig converters to change a 10gb X2 into 2x 1Gb SFP. 1Gb line cards in the 6500's use SFP's which use LC. 4948 1Gb use LC while 4948 10Gb use SC.

While things are working their way towards LC, I think it is something that experience or Google will tell you.

Heero

networker050184 wrote: »

Show interface status will give you what type of SFP is inserted.

This. All you gotta know is the type of fiber transceiver, and then you can tell if its LC or SC because a specific type of fiber transceiver will only ever use one style of termination.

ColbyG

Trifidw wrote: »

I'm not too sure that rule applies to well. The Sup6e in our newer 4500's use X2 modules with SC along with the 10Gb in our 6500's. But you can get twin gig converters to change a 10gb X2 into 2x 1Gb SFP. 1Gb line cards in the 6500's use SFP's which use LC. 4948 1Gb use LC while 4948 10Gb use SC. While things are working their way towards LC, I think it is something that experience or Google will tell you.

Right, that's why I said "This varies though". I'm just speaking of what you typically see in the wild. I should have also clarified that I was speaking of 1gig. 10gig makes everything even more complex.

Heero wrote: »

This. All you gotta know is the type of fiber transceiver, and then you can tell if its LC or SC because a specific type of fiber transceiver will only ever use one style of termination.

Sure, but you don't get that from sh int status. A better bet is show inventory [raw], but that won't be consistent either. The best option is to look up the model.

sides14

A vast majority of the new Cisco equipment is LC connectors (high port density) - 6500, 7609, CRS. Juniper M320s have some SC modules. It really depends on your switch, but if is uses SFPs, it is most likely an LC connector.

Forsaken_GA

sides14 wrote: »

A vast majority of the new Cisco equipment is LC connectors (high port density) - 6500, 7609, CRS. Juniper M320s have some SC modules. It really depends on your switch, but if is uses SFPs, it is most likely an LC connector.

Well the first quick and dirty check I do is to see how many ports the card has. If it's 4 or 8, then it'll usually be using SC optics. If it's 16 ports, then you need to figure out if it's a fiber module or not. It'll usually be using SC connectors. If it's more than 16 ports, it'll be LC... I have yet to see a blade that supports more than 16 SC connectors, and that's just a simple matter of the size of the cards, you really can't fit much more than that onto a physical linecard at present dimensions.

Note: This applies to Cisco only. I have no freaking clue about other vendors.

For me, the bigger issue is making sure I have the right kind of optics. Ordering short-haul optics when you need long-haul is a costly mistake. Likewise, making sure you have the right kind of fiber (single mode or multimode) tends to be a much bigger issue than the type of connector.

sides14

yeah...you are telling me about optics. I had someone order standard long haul (LH) SFPs when the project clearly required extended range ZX SFPs. They could never figure out why the links wouldn't come into service. Small oversights can cause major network issues.

vinbuck

If I remember right, you could risk damaging the optics if you do it the other way around and hook up ZX SFPs for a short fiber run in a CO/Data Center without some kind of attenuation device.

EDIT:

Just found the link to that here

Cisco Small Form-Factor Pluggable Modules for Gigabit Ethernet Applications - Cisco Systems


And for those of you that listen to PacketPushers, you should know the trivia question of the day?

Q: How many times can an SFP be plugged and unplugged? (Yes this is a real question and yes there is a finite answer )

sides14

Yes depending on your link budget you could potentially damage the receiving side equipment. My issue was with not having enough light to support the far end equipment.

Heero

sides14 wrote: »

yeah...you are telling me about optics. I had someone order standard long haul (LH) SFPs when the project clearly required extended range ZX SFPs. They could never figure out why the links wouldn't come into service. Small oversights can cause major network issues.

I wouldn't really call that a small oversight, but yeah, dealing with all the different types of optics can be a bit of a pain in the ass.