ACE Module throughput

patrik.spiess · ‎10-07-2011

Hi

In the Datashhet of the ACE-Module (ACE20-MOD-K9) there is the following promise:

Throughput

16 Gbps*, 8 Gbps*, and 4 Gbps

We have a base license, so I assume we have a throughput of 4Gbps (gigabits per second).

Are these 4Gbps bidirectional or unidirectional?

Is it 2Gbps in one direction and 2Gbps in the other direction?

Imagine we have just 1 host (A) before the ACE module and just 1 host (B) behind the ACE module. Can I transfer data from A to B (unidirectional) with 4Gbps? Assume the hosts are connected with 10Gbps to the network and use multiple flows!

How can I measure the effective used bandwith on the ACE module?

What hapens, if host A tries to send data faster than 4Gbps? Does it deny single packets? Base on what? Does it deny additional sessions?

How do I know that the ACE runs at it's bandwith limitation?

Any Ideas?

Thanks

Patrik

Daniel Arrondo Ostiz · ‎10-10-2011

Hi Patrik,

See my answers inline:

We have a base license, so I assume we have a throughput of 4Gbps (gigabits per second).

Are these 4Gbps bidirectional or unidirectional?

Is it 2Gbps in one direction and 2Gbps in the other direction?

It measures the total throughput going through the box. It includes both directions. Also take into account that, for any traffic through the ACE, the packets are seen twice (client to ACE and ACE to server), so the effective throughput is half of the licensed one.

Imagine we have just 1 host (A) before the ACE module and just 1 host (B) behind the ACE module. Can I transfer data from A to B (unidirectional) with 4Gbps? Assume the hosts are connected with 10Gbps to the network and use multiple flows!

You could get up to 2Gbps unidirectional. This traffic will go through the ACE twice, adding to the 4Gbps license

How can I measure the effective used bandwith on the ACE module?

With the "show resource usage" command

What hapens, if host A tries to send data faster than 4Gbps? Does it deny single packets? Base on what? Does it deny additional sessions?

It will drop packets that go over the bandwidth without taking into account to which connection they belong

How do I know that the ACE runs at it's bandwith limitation?

Again, "show resource usage"

Regards

Daniel

patrik.spiess · ‎10-10-2011

Hi Daniel

You could get up to 2Gbps unidirectional. This traffic will go through the ACE twice, adding to the 4Gbps license

I don't agree with that statement. As far as I see, our link to the backup server has a maximum throughput of ~ 2.2 Gbps, which is above your stated maximum throughput.

Now, in the other thread we discussed the resource allocation. I did the following allocation:

ADMIN: limit-resource all minimum 5.00 maximum equal-to-min

NOZONE: limit-resource all minimum 10.00 maximum equal-to-min

ZONE1: limit-resource all minimum 10.00 maximum unlimited

ZONE2: limit-resource all minimum 10.00 maximum unlimited

ZONE3: limit-resource all minimum 10.00 maximum unlimited

ZONE4: limit-resource all minimum 10.00 maximum unlimited

So, this means, that my ZONE1 (where I have the performance issue) can only have up to 55% of all resources, because the rest is reserved as minimum for the other contexts.

Then just calculate: 2,2Gbps / 55% * 100% equals to exactly 4Gbps. This leads to the conclusion that the maximum throughput is 4Gbps, if I reduce all the contexts minimum to 0%.

Maybe it helps to know that we operate the module in layer 2 mode?

regards

Patrik