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qsfp+ SR4 distances when splitted into 4x10GBaseSR ifs

[ Edited ]
‎05-16-2016 08:28 AM

Hi,

 

I'm getting a little confused with max distances with qfx qsfp+.

 

QFX-QSFP+-40GbaseSR4 are given for distance of 100m over om3 mmf, 150m over om4 MMF.

I get it that we can configure the QSFP+  as a 40G unique channel or as 4 separate 10GbaseSR interfaces.

 

Simple question :

when split to 4x10GBaseSR separate interfaces,

-1/ does the max distances stated for QFX-QSFP+-40GbaseSR4 (100m@om3, 150m@om4) remain the max distances available on each 10GbaseSR interface ?

-2/ ... or does the max distance becomes the same as a native SFP+ 10GBaseSR interface (300m@om3, 400m@om4).

Not talking about the ESR4 qsfp+ here, just the basic SR4 qsfp+.

 

Juniper representative told me 1/ was correct.

Cisco told me 2/ was correct (on their boxes...).

So... who's right and who's wrong ...?

 

Pascal

3 REPLIES 3
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Re: qsfp+ SR4 distances when splitted into 4x10GBaseSR ifs

‎05-16-2016 11:24 AM

I would say 1). This is what is reflected in various materials.

 

It could easily be that Cisco has an optic which deliver 300m or 400m on OM3/OM4 so I think you should trust your Juniper representative 🙂

 


--
Best regards,

Jonas Hauge Klingenberg
Juniper Ambassador & Technology Architect, SEC DATACOM A/S (Denmark)
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Re: qsfp+ SR4 distances when splitted into 4x10GBaseSR ifs

‎05-20-2016 02:08 AM

Thanks Jonas.

Juniper just came back to me and confirmed that distances reachable out of a 4x10GBAseSR coming from a splitted SR4 QSFP are much lower than distances reachable with native 10GBaseSR SFP+.

They even advise not to go for SR4 optics but ESR4 instead, as SR4 optics send a initial signal that can exceed normal 10GBaseSR signal ranges, and cause warning on the peer equipment.

But ESR4 optics are much (much!) more expensive than SR4.

 

To summarize :

- QSFP+ SR4, 40G mode : 100m@om3, 150m@om4

- QSFP+ SR4, 4x10GBaseSR mode : 100m@om3, 150m@om4, not recommended (signal strength)

- QSFP+ESR4, 40G mode : 300m@om3, 400m@om4, no support for om2

- QSFP+ ESR4, 4x10GGBaseSR mode : 300m@om3, 400m@om4, no support for om2

- SFP+ 10GBAseSR : 82m @om2, 300m@om3, 400m@om4.

 

Pascal

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Re: qsfp+ SR4 distances when splitted into 4x10GBaseSR ifs

‎06-06-2016 11:20 PM

After searching online for 40G QSFP+ SR4/ESR4 optics, I agree with you that ESR4 optics are much more expensive than SR4. Maybe you can choose JNP-QSFP-40G-LX4,(150m over OM4 MMF, 2km over SMF). This  40G QSFP+LX4 optics can

can be used with both MMF and SMF without the need for any changes to the transceiver module. Seems more suitable for you.

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