10Gb uplink upgrade considerations

[tommyboay]

Hi everyone,

I have an office with a 4507R chassis running with sup engine V-10GE. The two 10Gbps interfaces are currently unused and I have a X2-10GB-SR module ready to be loaded in there. On the other end, I have 3x3560G delivering connectivity on the upper floor. Units are currently interconnected using 1000 base SX SFPs and everything is working fine. I just received a new 3750E with the 2x 10Gbps uplinks and was wondering if I could possibly make use of them to upgrade available bandwidth and simplify my uplink configuration.

My goal is :

- To interconnect at least one 10Gbps interface between sup V-10GE and 3750E using existing cabling between the two floors.

- To stack the 3750E with two 3750 (non E and not even Gb on the ports) to matching needed port density and administer one logical unit.

- Keep at least 1 Gbps uplink from a 3750 unit as secondary path to the core (which is also SPT root).

A few questions:

-  What should I verify to assess the feasability of the 1 to 10 Gbps upgrade especially on the physical fiber part ?

- Is it possible to stack 3750 and 3750E switches if IOS version are matching ?

And of course, all comments are welcome !

Thanks very much in advance for your inputs.

Thomas

[mcusine]

Hi Thomas,

Answering you second question, yes you can.

Q. Can I run Cisco Catalyst 3750 switches with Cisco Catalyst 3750-E switches in the same stack?

A. Yes, the two series are compatible. When the Cisco Catalyst 3750-E Series detects a non-E-Series Cisco Catalyst 3750, it will negotiate down from StackWise Plus mode to StackWise mode. Thus, the entire stack will now run in the original StackWise mode.

Check the next link :

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps7077/prod_qas0900aecd805bbea5.html

I don't understand your first question.

You need to check the distance, in 10Gb the multimode fiber reach to 300 mtrs different from 500 mtrs of 1GB, and the connectors of the fiber.

Rate if it help.

Regards,

Mauricio

[tommyboay]

Hi Mauricio,

Thanks for the first answer ! I couldn't find the reference myself.

In fact, my first question is just about the physical cable and connector requirements, if any, on MM fibers to carry 10Gbps.

The length of the fiber is no more than 30 meters all included for sure. I use LC/SC MM fibers.

I'm probably going to take twingig converters with me to ensure I can get the uplink working.

Thanks again for your help.

Thomas

[Mohamed Sobair]

Thomas,

First Question:

Yes Stacking can be done as per the previous poster

for your second question:

Yes indeed, you need to check the fiber part , there is type of fiber cables that can carry 10Gbps speed. usually you found (50/125) written on the fiber patch cable.

HTH

Mohamed

[Leo Laohoo]

To interconnect at least one 10Gbps interface between sup V-10GE and 3750E using existing cabling between the two floors.

Let me put it this way:  As per the previous responses to your topic, the 3750E can support 10Gb.  No problem.  The SupV, however, not really.  The SupV can support up to 6Gb bandwidth per slot.  This value of 6Gb is in HALF duplex.

In my humble opinion, don't bother unless you have money to burn.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information  contained within this posting without consideration and with the  reader's understanding that there's no implied or expressed suitability  or fitness for any purpose.  Information provided is for informational  purposes only and should not be construed as rendering professional  advice of any kind.  Usage of this posting's information is solely at  reader's own risk

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Posting

Alhough original 4500s chassis has a 6 Gbps slot limitation, the supervisor, I recall, provides a fabric so, in theory in with 5 line cards, you could have 30 Gbps to move through the uplink(s).  The sup V, I also recall, has sufficient Mpps to guarantee line-rate between its dual 10 gig uplinks and all the user slots.

[tommyboay]

Very interesting inputs ! Thanks very much leolaohoo and Joseph.

In my case, the 4507R chassis has its 5 linecards working with approx 60/70% active ports on each. I currently use 4 SFP slots on the Sup V-10GE for my uplinks (2 etherchannels). I never heard of a 6Gbps limitation for the sup itself, only for the line cards. What I did hear though was the necessity of using IOS 10.2(25)SG or higher to be able to use GE and 10GE ports at the same time. But my goal is to replace the GE SFP ports by single 10GE uplink on each of my sup running in SSO mode.

Since initial post and thanks to first comments, I found more information on the physical requirements for 10GB Ethernet : The OM1 standard defined by 62.5/125 µm (core/cladding diameters) can support it up to 33 meters. OM2 50/125 µm fibers will go up to 82 meters. Both OM1 and OM2 are designed for use with LED transmitters and therefore having limited range at this speed (10GE requires laser transmitter as LED cannot be turned on/off fast enough). OM3 50/125 µm laser optimized multimode fiber will go up to 300 meters minimum (Some can go to 550m).

Interesting WP on this topic here : http://www.nbm-distribution.co.uk/docs/10G_over_legacy_fibre_WP.pdf

Thomas

[Leo Laohoo]

4500 Models Comparison (Chassis and Supervisor Cards)

Data Sheet:  Cisco Catalyst 4500 Series Supervisor Engine V-10GE

[tommyboay]

"The SupV can support up to 6Gb bandwidth per slot.  This value of 6Gb is in HALF duplex."

This is totally NOT true. I took time to verify my belief and here is the math behind it (all numbers are taken from the sup V-10GE tab and got validation from Cisco tech staff) :

2 x 20Gbps (10GE full duplex)
4 x 2 Gbps (1GE full duplex)
Y x 12 Gbps (Y being the number of line cards @ 6 Gbps full duplex)

That ends up to 108Gbps per second of centralized bandwith on a 4507R. And this is the exact annound centralized switching capacity for the sup on my chassis. So to correct this : The sup V-10GE will offer 6Gbps FULL DUPLEX for EACH line card and capacity for full wirespeed on 2 10GE and 4 GE ports.

Be aware that if you use two supervisors in SSO mode, this limitation will NOT be extended : Only one 10GE and 2 GE ports per supervisor can be used.

So the supervisor V-10GE will offer me full blast on my 10GE port.

[Joseph W. Doherty]

Disclaimer

The    Author of this posting offers the information contained within this    posting without consideration and with the reader's understanding that    there's no  implied or expressed suitability or fitness for any    purpose.  Information provided is for informational purposes only and    should not be construed as rendering professional advice of any kind.     Usage of this posting's information is solely at reader's own risk

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising    out of the use or inability to use the posting's information even if    Author has been advised of the possibility of such damage.

Posting

My understanding is the the original 4500 supports 6 Gbps to and from a slot.  Leo's usage of half duplex might have been intended as such because sometimes duplex bandwidths are doubled.  For instance, 100 Mbps Ethernet port that supports duplex, was sometimes "advertised" as 200 Mbps.  Some of this still exists, for example, the original 3750 "32 Gbps" stack ring is dual 8 Gbps duplex connections (or so I believe).  The 6500 32 Gbps bus, in some Cisco literature is also described, as 16 Gbps, so it might be 16 Gbps duplex.

[tommyboay]

Agreed ! But it seemed strange to imagine Cisco marketing speaking about "wirespeed" 10GE ports that would actually not be able to reach 10Gbps.

I'm implementing my stuff tomorrow : 3x 3750E, 4x X2-10GE-SR modules and OM1 fibers with regular SC connectors.

Will let you guys know how it went.

Again, thank you all for your time and input !

[Joseph W. Doherty]

Disclaimer

The     Author of this posting offers the information contained within this     posting without consideration and with the reader's understanding  that    there's no  implied or expressed suitability or fitness for  any    purpose.  Information provided is for informational purposes only  and    should not be construed as rendering professional advice of any  kind.     Usage of this posting's information is solely at reader's own  risk

Liability Disclaimer

In    no event shall Author be liable for any damages whatsoever  (including,   without limitation, damages for loss of use, data or  profit) arising    out of the use or inability to use the posting's  information even if    Author has been advised of the possibility of  such damage.

Posting

I agree, i.e. when Cisco notes "wirespeed" the fabric design provides sufficient bandwidth (at least to the slot's bandwidth rating).  Actually, I recall that the supervisior's fabric bandwidth specs increase as the number of slots increase, for example 4507R vs. 4510R.

Also, if I recall correctly, for many of the later 4500 supervisors, forwarding rates, i.e. pps, also correspond with the fabric bandwidth to guarantee Ethernet "wirespeed".  It's not uncommon to find that specs fall short of "wirespeed" either for fabric bandwidth and/or forwarding rate.  (NB: in real world, true "wirespeed" guaranteed performance often not really needed, but makes for nice bragging/advertising.)