GLC-T and Cat 7

[salemmahara]

Hello everyone

I have 2 questions:

1. Imagine you want to connect your building floors (2960X) to your core ( 3850 ) using copper because your manager didn't accept fiber optic installation! Do you pick 2960X with 2 SFP+ uplink and use external transceiver ( fiber to copper ) to achieve 10Gb ? Or pick 2960 with 4 SFP and use cisco GLC-T to achieve 1Gb? I personally prefer GLC-T because third party vendors are not my choice ! But your opinion is really important to me. I mean, do you use external media converter or use cisco GLC-T ? Have you ever had any experiences like it ? Does Cisco advice external media converters ? I couldn't find anything in Cisco web site. ( Media converter in backbone !>!?!?!?!)

Note: we are going to use Cross Stack Etherchannel in our design , so media converter must be 100 percent reliable 

2. Does GLC-T support Cable CAT 7 S/FTP ? I mean, our backbone cabling is CAT 7 so if we pick GLC-T it must be compatible. Cisco says it's compatible with Cat 5 but we have already cat 6a f/utp and GLC-T and it's working just fine .

[Mark Malone]

Hi

1 I think that's really a personal choice , fibre is always better in my opinion where possible for the obvious reasons that its better than copper , a transceiver should make no difference we have had to use them before and have never really had issues with them , saying that a GLC-T will work fine too I use them in our 7ks and other platforms like 4431s  , maybe other users have diff experiences so hopefully they can add on to this as well , the more people that add something may make it clearer for you to base your decision

2 It should support Cat7 ok as its 1000base T same as GLC-T

Name	Medium	Specified distance
1000BASE-CX	Shielded balanced copper cable	25 meters
1000BASE-KX	Copper backplane	1 meter
1000BASE-SX	Multi-mode fiber	220 to 550 meters dependent on fiber diameter and bandwidth
1000BASE-LX	Multi-mode fiber	550 meters
1000BASE-LX	Single-mode fiber	5 km
1000BASE-LX10	Single-mode fiber using 1,310 nm wavelength	10 km
1000BASE-EX	Single-mode fiber at 1,310 nm wavelength	~ 40 km
1000BASE-ZX	Single-mode fiber at 1,550 nm wavelength	~ 70 km
1000BASE-BX10	Single-mode fiber, over single-strand fiber: 1,490 nm downstream 1,310 nm upstream	10 km
1000BASE-T	Twisted-pair cabling (Cat-5, Cat-5e, Cat-6, Cat-7)	100 meters
1000BASE-TX	Twisted-pair cabling (Cat-6, Cat-7)	100 meters

[salemmahara]

Thank you Mark

Have you ever use them in backbone ? Could you give me more detail about the project in which you use external media converter ? And also about used protocols and technologies in that please.

And please copy the reference URL for the table.

Thanks a million 

[Mark Malone]

Hi

Does not really matter what the protocols are running across the medium , its a physical layer connection the protocols are logical they will run across any medium provided it makes no diff if its eigrp /ospf etc or whether its copper or fibre , I have had layer 2 and 3 connection across both GLCTs and transceivers

one of the setups I had to use GLTs coming from core 7k fibre mod to patch panel and off then to 3750x MGMT switch , that's still in place works fine

a long time back , we had to use external transceivers connected to non fibre switch back to a vss 6500 fibre mod as copper blades were full, until we upgraded far end switch to support fibre as well and then went full fibre

Like everything when you introduce something extra into the path it is another point where something can go wrong or break so you need to take that into account as well when using transceivers but when I have used them they were stable until we removed them for other reasons

[salemmahara]

Mike, I've read media converters have some problems with etherchannel because they can't understand control protocols.

Have you ever run a complex setup like etherchannel or a multi-path link to somewhere like core? I mean, have you ever run redundant paths or etherchannel using media converter? They must be good to implement a simple connection. We have one of them to connect to switches together ( media is fiber and both sides are copper port ). 

Anyone there who can help me about GLC-T and CAT 7 and complete Mike's experiences ?

[Mark Malone]

Hi

I haven't ran ether channel back to core with media converters they were always orphan links which I never had an issue with but I do see what your saying so I would be very careful on the vendor you use for buying these , seems some have issues with certain control packets alright

https://www.perle.com/products/ethernet-to-fiber-media-converter.shtml

https://supportforums.cisco.com/discussion/11999901/etherchannel-problem-over-media-converter