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ISP Load Balancing


It is my first time subscribing to Expert-exchange, I am in mid-career PS Engineer, and i have my first inquiry

We are having two links, one about 100 Mbps ,, other about 150 Mbps or more

We want to supply to two types of customers, one is through a wimax network,, other is dedicated service

-goal 1 :We want to have these two inputs (wimax and dedicated) share the 100 and 150 Mbps links

We don't want at any time to find one of the links congested,,, and if the two links are to be congested ,,, i.e max traffic ,, we want the dedicated service users not to feel the congestion and not to be effected

-goal 2: this is to be done later ,, when link is congested for the system to detect it fast and limit the p2p and download traffic ,, to make browsing faster and congestion undetectable by customer as any degradation in service

What we have in mind till now is the following

Solution 1: Cisco Router

-Pros Cisco Router can provide as many inlets and outlets as you desire,, can provide BGP for multi-homing , cheaper than other solutions

-Cons You cannot provide very accurate load sharing, the suggested method is having 2 default routes with equal metrics

At best this will provide ,, 100 Mbps to both links ,, and when one link is congested ,, Link1 ,,, the other link : Link2 will be free ,,,

Solution 2 : Baracuda link Balancer

-Pros Very good Load balance for different BW links

-Cons only one inlet, and doesn’t support source ip routing + it doesn’t make route policy for Cache server

Solution 3 : AscenFlow

Pros   good DPI integrated for type of service detection and source IP Address QoS

Cons: expensive and not sure if it detect congestion,, + not supporting load balancing, cannot be used as edge router

We haven't tried any of these solutions before ,,, so any suggestions from the experts ?
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Senior Network Engineer
Top Expert 2012

I'd use a server with redundant hardware, running zeroshell:

Cisco routers aren't too good for load balancing without routing protocols;
Barracuda gear is usually nice, but too simplified for your problem, like QoS for p2p traffic.
I've never used AscenFlow before, but if it can't load balance, then it's not for this task.




Is ZeroShell really for ISPs ?

I have read about it before ,, but as i understood ,, ZeroShell run live from CD ,, and it cannot be installed on a Linux machine

If we want to use routing protocols, can we load balance 150, and 100 Mbps links  in a good manner,,, with lets say , OSPF ?
TimotiStSenior Network Engineer
Top Expert 2012
According to the zeroshell website: "It is available in the form of Live CD or Compact Flash image". It can be installed on a server.

The one and only routing protocol between ISPs is BGP. It's robust, scalable, wonderful, but really not trivial to setup in a full load-balancing, redundant, highly-available config.
Also, BGP won't do you any QoS, that's a different topic.

If you want to be a real ISP, you can buy a Cisco/Juniper router cluster, and a NetEnforcer/AscenFlow/other QoS appliance cluster, maybe a firewall cluster and a spamfilter cluster, but judging from your original post, that would be going a bit overboard.

I don't know the size of your operation, but I'd stick with a less elegant, but all-in-one solution with policy routing. In my opinion, this will most likely be some sort of a Linux/BSD box, like Zeroshell, maybe IPCop, or something like them.



Hi, Thanks for your help

Will cisco router 7201,  be good enough to implement BGP here ?

Actually, we already have Wimax Network from Huawei with Redundant Firewall at the edge

Now we are planning to expand our connectivity with the other link

Any idea how reliable will IP cop and other similar solutions will be with high traffic ? we have till now more than 350 requests/sec with about 100 Mbps link

Will the traffic go smoothly without any delay or jitter ,,, will the network be stable enough and will we have high availability ? if so ,, how we can make it by default to bypass the IPCOP or similar server if any failure happen ?

Thanks for your help and support


Hi TimotiSt

Will a normal router with routing protocols support the above scenario ?
TimotiStSenior Network Engineer
Top Expert 2012

Yes, the 7201 should be able to handle pretty much everything at 100/150 Mbit speeds.

Since this is starting to look like a bit more complicated scenario than I first believed, I think maybe you should contract an experienced network engineer to design the new network topology and liaise with your upstream ISPs on things like BGP peering, failover, etc.

It looks like you need a mixture of some solutions. We provide and install both the AScenlink and the BArracuda.
but your setup seems a bit more complex. Cisco router wont be that ideal of a choice for what you want to do.

you should however have a look at the following :


In and ideal setup you would have a link balancer, a bandwidth controller and a Cache engine that would give you a terrific service to the customers.... but again, it depends on what you really want to achieve and what budget is available.

you can contact me if you need further help on the design side of the topology.  We have been supplying and supporting ISPs..

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