Bonded ADSL

Posted on 2009-12-26
Last Modified: 2012-05-08

I want to increase the upload of all our VPN connections.

I wanted to know how this can be achieved using Bonded ADSL.

Currently we have a VPN setup between fortinet firewalls using 1 static IP at each site.

We have seen some multilink routers from Draytek etc, What i am trying to get my head around is how the VPN traffic will be managed through the internet if there are multiple ADSL lines at each site.

We are considering bonding 2-3 ADSL lines accross 5 sites and then VPN between them.
Question by:jkacha
    LVL 2

    Expert Comment

    Depending on if you are located in the US, once you have bonded 3 ADSL lines at each site you likely end up with T-1 uploads as an aggregate, why wouldn't you just get an T-1 to the internet and skip the bonding and issues associated?  The cost will be roughly the same at each site and if you want redundancy then get a DSL connection.  As far as managing VPN traffic, look at white papers for Barracuda and/or Xnetworks.  Both of these provide link bonding solutions for multiple ISP connections.  Best of luck.  
    LVL 3

    Author Comment

    We are based in united kingdom, london
    LVL 2

    Assisted Solution

    Okay, E1 in that case.  That makes more sense because we don't find 2 or 3 DSL providers coming into one building in the US very often.  Take a look at how Barracuda and Xnetworks work with VPN.  If your equipment can not do the same I am sure you can find a dealer across the pond.

    Best of luck!
    LVL 4

    Assisted Solution

    We used bonded ADSL for our internet connection in the UK..We dont run vpn on it though so I cant comment on the performance of vpn over it.

    bonded ADSL connections terminate on the equipment provided by the bonded ADSL provider and you just get a single ethernet handoff that you connect to your equipment.

    I belive the provider uses their own encapsulation on the lines and terminates them on a bonder at the other end which is how it works over multiple ADSL lines.

    There is an overhead on the connnections also If you get get 3*4Meg ADSL connections you'll probably get about 9meg total.

    Just remember also that its ADSL so for your vpn connections they'll get good speeds downloading email but poor sending email and files to you as you dont get anywhere near the same upload speed.

    We use a company managed communications in the UK. They are OK, I wouldn't say the uptime is anywhere near the 99.99% they suggest, nearer probably 95%.

    If you want proper reliability then you are looking at E1 type connections.
    LVL 4

    Accepted Solution

    bonded adsl, normally have one provider, when i did some bonded adsl solutions when i was a bit younger, the separate adsl lines normally bonded and had 1 logical IP ( using multi-link ppp), so from the perspective of vpn connections it should work

    i doubt the upload performance will be much improved,  i agree with dylan , if you really want to improve upload performance, check out the pricing for E1 connectivity for your sites ,  2mbs upload/download  non contended beats  any kind of adsl for performance and reliability.


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