Router throughput Cisco 867vae vs ISP provided router

[davidfield]

Anyone able to assist with some stats here.

Basically I have a client who has a new Fiber service from BT in the order of 300mbps. Fiber into his house with and Openreach Fiber termination modem - ONT  in bridgemode to a Homehub5.   On our 867VAE router we are doing PPPOE through the Gig1 port to the ONT replacing the homehub5. 

The client says hes only getting 100mbps downloads. I can't say at this time what he is using for speedtest or contention but BT are saying they are delivering 300mpbs so now I'm in the situation where he is questioning the Cisco router.  2 questions if I may and hopefully someone can offer some advice/links.

- Has anyone got any stats on the switch backbone on the 867vae.  I've checked the data sheets etc.. and all I can find is stats on the VDSL which is max 150mps.  I'm plumbed into the Gig interfaces for WAN and LAN so I would assume the backplane (excluding firewalling etc..) should be able to handle a gig throughput between the PPPOE, Gig1 port to the LAN.

- A more basic question.. I know that on order to get high throughputs I've always needed to buy high spec ISR routers 2900's etc..  How can a BT Homehub5 and other providers these days now be offering a little plastic routers and say they are giving a 300Mpbs throughput?  Surely the real throughput is much less when packet sizes comes into it let alone firewall etc.

Any advice appreciated.

Thanks

Dave

[Leo Laohoo]

800-series routers cannot support 300 Mbps.  You're probably talking about a 3925E to be able to support 100 Mbps upload AND download.  

When you mean "300 Mbps" does this mean the sum of the upload and download or is it one-way-traffic only?

[davidfield]

Thanks Leo,

I'm talking one way traffic.  ie.  300Mbps down and 30 up.

Re the 800 series router.  Given I'm using the Gig WAN port would this not be the Gig switch backplane providing port to port speeds or is the limitation here the processing power to re-write the packets.

Do you have any thoughts on why a carrier can provide a cheap router and claim that can deliver 300Mbps download speeds yet for a Cisco router as you mentioned above I'd need a 3900 series router?  There is a huge difference in cost and hardware spec and surely the cheap provider router cannot have the processing power.

Thanks

Dave

[Leo Laohoo · Accepted solution]

Do you have any thoughts on why a carrier can provide a cheap router and claim that can deliver 300Mbps download speeds yet for a Cisco router as you mentioned above I'd need a 3900 series router?  

I do.  Because they do NOT expect end-user, like you, to know.  So it's easier (and cheaper) for you to get a tiny Cisco router (in your case, an 860) that is rated to about 12.8 Mbps of one-way traffic and charge you for traffic you won't be able to use than to give you a real router that will do 330 Mbps of one-way traffic. 

Have a look at THIS document.  You'll see in this document what the router is really, really rated for and it sure can't go beyond 12.8 Mbps.  So what BT may have done is made the packet size SMALLER so that it'll look like it's pushing a sh1t-ton of traffic when in reality, it doesn't.  

[davidfield]

Thanks Leo,

This makes sense re the actual carrier router capability, but the speedtests showing that it is possible to get 300mbps aren't helpful.  Would it be that this is a really small packet test but when you actually put decent sized packets through the router performance limits get hit.

I've had a look at the document which is about 6yrs old.  Wouldn't the current series routers be capable of much more.

Sorry to labour this but am trying to build a response to the client.

Regards

Dave

[Leo Laohoo]

I've had a look at the document which is about 6yrs old.  Wouldn't the current series routers be capable of much more.

The document is 6 years old because the team that used to update this document regularly got dissolved in 2010.  

Have a read of THIS.

IF you want to have a router that can support 330 Mbps then you should, ideally, be looking at the newer 4431 and this model supports a DSL module.

Another thing ... Your client has an 860 with a DSL sub-model.  I've never heard of DSL that can do >50 Mbps.  This means that the router has to be, literally, sitting on top of the DSLAM.  

[franklinb]

Hi Leo, VDSL can easy reach over 50Mbps:

http://www.increasebroadbandspeed.co.uk/2013/chart-bt-fttc-vdsl2-speed-against-distance

[Joseph W. Doherty]

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Posting

ISRs are generally software (i.e. CPU) based, and their forwarding performance depends very much on packet size and what they are configured to do.  (Leo's reference to Cisco's ISR performance white paper shows the range of performances under different usage conditions.)

Other vendor "little plastic routers" might have a much higher throughput because they also might have dedicated hardware.  (Contrast the performance of Cisco's small L3 switches, which often offer wire-rate for multiple gig ports.)

[Leo Laohoo]

Joe, 

I'm really curious or mystified, but have you heard of a DSL "solution" that can push 300 Mbps (upload or download speed)?  I know I haven't. 

[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

Leo, none that I've worked with.  However, wiki does have a few that offer very high data rates at short distances, e.g. G.fast (http://en.wikipedia.org/wiki/G.fast)

[Leo Laohoo]

Yes, I've heard of "G.Fast" but this technology just came out about 8 months ago and even Cisco hasn't released a router that'll support this.  

[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

Leo, none that I've worked with.  However, wiki does have a few that offer very high data rates at short distances, e.g. G.fast (http://en.wikipedia.org/wiki/G.fast)