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About Nexus 7018 Switching Capacity

CHIEN-HSING WU
Level 1
Level 1

Hi,

Does anyone know the maximum switching capacity of Nexus 7018?

Can I say the capacity is 230Gbps*16 since the fabric architecture provides 230Gbps per slot with 5 fabric modules?

In the datasheet, Nexus 7018's performance is 960Mpps (Ipv4 unicast) in combination with supervisor and fabric modules.

How to calculate the performance 960Mpps?

Thanks.

David Wu

1 Accepted Solution

Accepted Solutions

Amit Singh
Cisco Employee
Cisco Employee

David,

Each slot on N7K is capable of switching upto 550 Gbps per slot. This is available with the Generation 2 fabric module (FAB 2), which supports 110 GBPS per slot capacity.You can use 5 of these in a N7K chassis which has upto 5 Switch fabric slots. 110*5 = 550 Gbps per slot capacity.In a full-duplex mode, N7K with FAB 2 will support 15+ Tbps switching throughput.

Cheers,

View solution in original post

10 Replies 10

Ganesh Hariharan
VIP Alumni
VIP Alumni

Hi,

Does anyone know the maximum switching capacity of Nexus 7018?

Can I say the capacity is 230Gbps*16 since the fabric architecture provides 230Gbps per slot with 5 fabric modules?

In the datasheet, Nexus 7018's performance is 960Mpps (Ipv4 unicast) in combination with supervisor and fabric modules.

How to calculate the performance 960Mpps?

Thanks.

David Wu

Hi David,

As per the datasheet The Cisco Nexus 7000 18-Slot Switch delivers and Designed for future scalability to switching capacity of more than 15 terabits per second.

http://www.ciscosystems.com/en/US/products/ps10098/index.html

MPPS stands for million packets per second and Cisco prefers to refer throughput in MPPS. For a layer-3 switch an MPPS value is shared one. For some of the higher-end Cisco routers the routing is "distributed" between multiple line-cards

For example, 2960-48PST-S is 13.3 Mpps.


The figure MPPS expresses the maximum number of frames per second that can be processed by the device. It is not dependent on frame size but clearly small frames require higher packet rates.


To give you an idea of what this number says:

Smallest frames in Ethernet are 64 bytes in size, taking in account the preamble (8 bytes) and the minimum inter-frame gap (the last two counts roughly for 20.2 bytes) to fill a GE port in one direction you need 1484560 frame per second.

10^9 / [(64+20.2)*8] where 8 is bits/byte.

So a number of 13.3 MPPS is equivalent to [((13.3 M * (64+20.2) * 8)) / 10^9 = 8.95 / 2=4.47] 4.47 GE ports filled with smallest frames bidirectional.

Hope to Help !!

Ganesh.H

Remember to rate the helpful post

Hi, Ganesh:

Thanks. Your description are very clear.

Regards,

David Wu

Hi, Ganesh:

Thanks. Your description are very clear.

Regards,

David Wu

Hi David,

If the post are answered your query,It will be helpful to mark the thread as answered so that other also get beniftted.

Ganesh.H

Hi Chien-Hsing Wu, I just ran into this post, sorry I couldn´t reply to your original one. Since I did not see an explanation on how to get 960 Mpps, I included one for you:

The 960 Mpps number you mentioned is calculated taking in account modules with one M1 forwarding engine, which is the case for modules such as N7K-M132XP-12, for example. Other modules use a M1 forwarding engine (some newer modules use even 2 forwarding engines).

The "M1" indicates the forwarding engine is M Series, first generation and is capable of delivering 60 Mpps of Layer 2 and 3 IPv4 unicast or 30 Mpps of IPv6 unicast for all ports on that module.

You can use up to 16 I/O Modules on the 7018, which brings the 16 (forwarding engines)* 60 (mpps if M1)  = 960 Mpps.

Be aware that more recent modules use even dual M1-XL forwarding engines, delivering 120 Mpps L2 and 3 IPv4 unicast or 60 Mpps IPv6,  and others use F1 forwarding engines, delivering 480 Mpps of distributed L2 unicast per module.

On the other hand, regarding the calculations you suggest with 230 Gbps, some documentation shows 7.8 Tbps as total switching capacity for the 7018. You get that number assuming you are using Fabric 1 modules, or Fabric modules from 1st generation. If this is the case, calculation is as follows:

     230 Gbps per slot for the I/O related slots

     115 Gbps for the supervisors

     (16 * 230) + (2 * 115) = 3910 Gbps, and taking in account full duplex transmission we multiply this by 2 and get the 7.8 Tbps.

As mentioned by Amit Singh, if we use Fabric 2 modules each slot could *potentially* use 550 Gbps (depending on the module), which is the total crossbar bandwidth available for each slot if your chassis is equiped with 5 Fabric 2 modules, as opposed to the 230 Gbps when the fabric modules are 1st generation modules.

HTH

Leo Pastor

Amit Singh
Cisco Employee
Cisco Employee

David,

Each slot on N7K is capable of switching upto 550 Gbps per slot. This is available with the Generation 2 fabric module (FAB 2), which supports 110 GBPS per slot capacity.You can use 5 of these in a N7K chassis which has upto 5 Switch fabric slots. 110*5 = 550 Gbps per slot capacity.In a full-duplex mode, N7K with FAB 2 will support 15+ Tbps switching throughput.

Cheers,

Hi, Amit:

So that explains it.

Thanks.

Regards,

David Wu

asingh2 wrote:

David,

Each slot on N7K is capable of switching upto 550 Gbps per slot. This is available with the Generation 2 fabric module (FAB 2), which supports 110 GBPS per slot capacity.You can use 5 of these in a N7K chassis which has upto 5 Switch fabric slots. 110*5 = 550 Gbps per slot capacity.In a full-duplex mode, N7K with FAB 2 will support 15+ Tbps switching throughput.

Cheers,

Hi Amit

Don't know whether you will see this but thought i'd try.

I am familiar with 6500 switch fabric capabililties but am struggling to come up with comparable figures for the Nexus 7000. The 6500 with a sup720 supports up to 40Gbps per slot (80Gbps soon with new Sup 2T i believe).

I thought i read somewhere that the Nexus supported up to 80Gbs per slot but you seem to be suggesting that actually it can support up to 550Gbps per slot, which is obviously an awful lot more. Is this with the addition of extra cards or fabric modules ?

And are you saying that across the entire 18 slots each slot could support up to 550Gbps throughput ?

Could you perhpas go into a bit more detail about how the figures are calculated.

Jon

Hi Amit,

I agree with Jon.  By looking at the details I have the following information for 7018 today at its maximum based on cards I can purchase today:

Scenario with Nexus 7k and Fabric Path:

-          46Gbps per fabric slot

-          5 fabric slots

-          230Gbps per slot with only the F-Series card

-          368 Non-blocking 10GE ports for the total system

-          16 links in link aggregation max today

-          16 ECMP Paths max today

Allowing me to have the following if I wanted a completely non-blocking uplink and user port configuration:

184GE Uplinks with 184GE to end nodes where this will only work in Layer 2 in this scenario because of Fabric Path and the F series card.

Since I would have to equally distribute this over 16 spine Nexus 7k I will choose to use the following:

11 10GE ports per port-channel for each spine uplink with connection to all 16 spines.  This will be a 176 10GE uplink and providing 192 10GE to the end nodes.  Not quite the fair uplink and end node non-blocking balance.

Can you check if this is correct?

Thanks!

Charles

Hi Guys,

Each fabric has two physical traces to each line card, each trace capable of 23Gbps. Which means each fabric can deliver 46Gbps to each module. With 5 fabric modules installed that allows you 5*46 Gpbs = 230Gbps per slot. The current capabilities of the M-series of line cards is that they can handle a maximum of 80Gbps (this is a limitation of the linecard, not the fabric, so this is very seperate to what the fabrics can deliver). These figures are current, based upon what you can purchase today. This means with your current line cards you are using 80Gbps of a possible 230Gbps.

In the future Cisco will be releasing M1 Series 16 port 10G modules capable of 160Gbps/ slot (16 ports @ 10Gbps full line rate). The F1 series cards capable of 230Gbps/ slot, and the F2s will be capable of upto 480Gbps (48x 10Gbps ports). Future fabrics will support up to 550Gbps/ slot. Which means they will more than satisfy the needs of the future F2 modules. To fully utilize the M1 or F1 modules you can get away with 5 of the current fabric modules, but the F2s will require the new fabric modules.

So in answer to thequestion... The Nexus itself is capale of far more than it is curently today. The expected release for these cards is supposed to be in the 2nd half of calendar year 2011, so hopefully we are not too far away!

Hope that helps

Nick

leopastor
Level 1
Level 1

Seems the posts here are out of date order!

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