G.655 fiber and GLC-LH-SM GLC-ZX-SM

Hi!

I have a project which uses Cisco catalyst switch 2970 for two sites,
connected by G.655 single mode fiber. Depending on the distance, I
will be using either GLC-LH-SM or GLC-ZX-SM SFP transceiver module for
my switch.

From Table 2 SFP Transceiver Module Cabling Specifications
in the URL
http://www.cisco.com/univercd/cc/td/...c/78_15160.htm
, the SMF fiber recommended for GLC-LH-SM or GLC-ZX-SM is G.652.

However, the fiber will be G.655 instead of G.652 standard.

My question is whether there will be any issue using G.655 fiber for
GLC-LH-SM or GLC-ZX-SM?

If not, assuming that I cannot change the fiber to G.652, is there
any solution?

Thank you very much for any pointers and advice.

Best regards

Stonewealth

stonewealth

"stonewealth" <> wrote in message
news: oups.com...
> Hi!
>
> I have a project which uses Cisco catalyst switch 2970 for two sites,
> connected by G.655 single mode fiber. Depending on the distance, I
> will be using either GLC-LH-SM or GLC-ZX-SM SFP transceiver module for
> my switch.
>
> From Table 2 SFP Transceiver Module Cabling Specifications
> in the URL
>
http://www.cisco.com/univercd/cc/td/...c/78_15160.htm
> , the SMF fiber recommended for GLC-LH-SM or GLC-ZX-SM is G.652.
>
> However, the fiber will be G.655 instead of G.652 standard.

if you look at:
http://www.ciscopress.com/articles/a...&seqNum=7&rl=1

it implies that the G.655 fibre is "better" quality - similar loss, and
lower dispersion than base G.652.

the description here also implies G.652 is the baseline, and the other
variaties mentioned are improved for various applications.

FWIW most of the issues mentioned are only a problem at higher speeds (say
10G), with DWDM, and /or long distances, so as long as you are not trying to
push the limits on the kit you use you should be OK.
>
> My question is whether there will be any issue using G.655 fiber for
> GLC-LH-SM or GLC-ZX-SM?

i think it will be OK - but you arent paying for formal professional
opinions on Usenet........
>
> If not, assuming that I cannot change the fiber to G.652, is there
> any solution?
>
> Thank you very much for any pointers and advice.

go to whoever you are buying the cisco gear from and get them to issue an
opinion (preferable backed by Cisco, and in writing).
>
> Best regards
>
> Stonewealth
--
Regards

- replace xyz with ntl

Hi!

For the benefit of those who is following this thread, I just got
reply from Cisco engineer, so I would like to share the knowledge with
the group:

" Cisco does not certify the use of the G.655 fiber with Gigabit
Ethernet. It does not mean that it would not work but the distance
could be impaired. For example, if you use G.655 fiber with the
1000BaseLX/SX cable, its response would be like a multimode fiber
instead of a singlemode fiber. The reason is that the G.655 standard
specify that the cable cut-off is <1480nm and 1000BaseLX/SX cut-off
needs to be max 1270nm.

For the 1000BaseZX GBIC, it uses the 1550nm so would be closes to
what you could be using. So you might probably explore using this GBIC
instead of GLC-LH-SM for distance < 10km if you are using G.655 fiber
instead of G.652 fiber. In this case, you need to check if any
attenuator is needed if the cable is too short to reduce the power. "


Best regards
Stonewealth

[alwong]

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