Bandwidth Rate Limiting

datasnake · 21st March 2007

We have a customer which we need to provide a capped data service to. ie limited to 20Mbit rather than be on a 95% billing system.

Our switches don't appear to offer this feature, is there another way we can approach this to make it happen?

SynergyWorks · 21st March 2007

What switches are you using? I'd be suprised if they don't support it. Even the most basic rack-switches we have support QoS Rate Limiting / CIR - and i'm talking switches sub £200.

datasnake · 21st March 2007

Our switches are HP Procurve 2650, which I see do have QOS functionality. I don't see how to rate limit with this though

markcastle · 21st March 2007

You can't do rate limiting on those HP switches as far as i am aware.

One option would be dummynet. You can get this with a relatively simple to configure web based interface with m0n0wall.

... or buy a different switch.

A1ISP · 22nd March 2007

You need layer 3 switching capabilities. Something like an Extreme Networks 48 or 24 will do the job and can be purchased on Ebay for around £50.00. Check with the seller the switch has the layer 3 license as this is a pay for serial key that is required.

I hope this helps.

SynergyWorks · 22nd March 2007

You don't need Layer3 capabilities to do rate limiting. I've many a layer2 switch doing rate limiting without issues.

datasnake · 23rd March 2007

Can you suggest a cheap switch that will handle this, preferably with just 4 or 8 ports?

A1ISP · 23rd March 2007

I am not aware or have any experiance of the bandwidth and bust limiting layer 2 switches so can not advise on that. However, I can say that if it is going ot be rack mounts, then a summit 24 is 1U and would take the same space too.

Another thing to keep in mind. Don't get drawn into the same trap as most and just buy a switch. There is a vast array of differences in their ability to swich at speed. For example, the Summit has a 17.5 gigabit per second switching fabric. Some switches will be 17 times slower!! IF you are OK with ping speeds dropping as the bandwidth increases, go for the cheap end planets, 3Com's HP's etc. If not, Cisco and Extreme are your best bet. In my opinion of course!

JJ

andyb28 · 23rd March 2007

THIS USER HAS BEEN GAGGED BY THE FORUM HOSTS FOR SPAM OR BREAKING THE RULES...
User will be ungaged in around 78 hours from this post.

Karl · 23rd March 2007

Err.... any decent switch will switch at wire speed these days, they'd be pretty nasty if they couldn't. Where the difference is, is in Layer 3 switching capabilities due to TCAM size limits - So once they hit the TCAM limit they have to fall back to software switching.

[edit]Also Layer 3 "switches" tend to be flow based, which generally makes them poor in DoS situations compared to a pure packet by packet Layer 3 router. The reason being due to the ability to setup flows, which takes time/resources.

A1ISP · 23rd March 2007

My comment does not mean all HP switches are crap or do not perform, it refers to the fact that HP (and others) do make 'lower performance' switches where generally, Extreme and Cisco are all high performance.

aXeR · 23rd March 2007

A1ISP, I'm sorry but advising people based on an ill-informed opinion that seems to have no foundation is stupid! As per Karls’ comment, practically any modern rackmount switch (even desktop for that matter!) will switch at wire speeds. As for insinuating that 3com and HP are in the same league when it comes to decent switches - lol! HP managed switches are up there with the best considering their price, speed and reliability!

EDIT: I wrote this before your reply above btw :P

A1ISP · 23rd March 2007

Oh Dear, I guess every forum has it's egos...

Karl · 23rd March 2007

No, not egos, just people who don't like sweeping generalisations. Especially when it's well known that most Cisco kit can't get anywhere near the stated specs on throughput in the real world.

As for £50 24 port Extreme switchs from eBay - They'll most likely be pre-recall 24e3 units, which are faulty, generate spurious traffic then eventually die.

aXeR · 23rd March 2007

A1ISP, can I suggest staying clear of public forums if you take offence easily to being question when you make bold, unfounded claims?