ADSL Bonding – How To and Review

Submission by Paul Gale – In the desire to increase my upstream speeds as much as possible I did some research into ADSL bonding or MLPPP (Multi Link Pont to Point Protocol). A handful of ISP’s offer support for this (they tend to be smaller companies though rather than the likes of BT, Yahoo etc). After a fair bit of hunting around and talking to people, I plumped for 3 x ADSL Max Premium (Office) connections from a reseller, UKFSN (, of an ISP called Enta Net (

UKFSN is a one man band but crucially, all support is direct from Enta Net who in my experience have a fairly good level of manning. They tend to answer the phone reasonably quickly although email support can be a bit slow. Enta Net won’t deal directly with small businesses and home users, which is why a reseller comes into the equation. Enta will deal direct if you want a Cisco managed bonded router solution though but this is a fair bit more expensive.

Each of the three lines would provide me with up to 8Mbps downstream and 832Kbps upstream (the home or standard product gives 448Kbps upstream). The Premium or Office product supposedly gives higher priority to your traffic in BT’s network along with the higher upstream speeds. Contention ratios are no longer used to differentiate the products on BT’s IPStream network that Max uses. Each of these lines would be bonded together using MLPPP -“ both at the ISP and at my end using a Linux based self-built PC router and using free software from FreeStuffJunction ( Each connection is plugged into a Sangoma S518 PCI ADSL modem (one for each connection), costing £112 each.

The router boots and runs from CD ROM or a write-protected USB pen drive, increasing security. In my case, my old main board didn’t support booting from USB pen drive so I used a hybrid solution of a boot loader from CD which then hands over to the main o/s held on the pen drive. Configuration files for the connections and services such as IPTables, the Linux firewall etc are held on a second pen drive. The router software is fully featured and supports IPSec VPN, NAT, Firewall, Squid proxy cache, traffic shaping, DHCP, Snort intrusion detection and SNMP amongst others.

Setup and configuration of the router was really simple. The whole package is supplied as an .ISO image and you simply have to set a few configuration options which take the form of a number of text files (Just the existence of the file sets the option in most cases). Once up and running, the router is managed by a modified version of Webmin, the Linux web based admin system. In-depth knowledge of linux is not needed unless you really want to get ‘under the hood’. Once all lines have been brought up and bonded, there are a number of reporting and information options available from Webmin. The software also runs a script, checking on the status of the lines and re-bonding if one should fail. So far, over the couple of months the router has been running, I’ve not had any problems. Support from the developer and fellow users is available free via a forum and an expensive premium rate phone number if you can’t wait for a reply via the forum.

The router works on any old 486 and up PC you might have lying around. You need to ensure it has enough PCI slots to accommodate the PCI ADSL cards though. The router also supports bonded SDSL but requires a different card type for this.

So what was I expecting from this solution? The maximum theoretical downstream rate in my case is 24Mbps and upstream 2.5Mbps (approx). Of course, this is the sync speed – data throughput rates will be less due to IP overheads etc.

To get the three ADSL lines into my office, I had to migrate one existing 2Mbps service from Eclipse, convert a Home Highway line to analogue and get a third analogue line installed – quite a job – and, you guessed it, none of it went smoothly! Most problems were caused by BT failures or problems, both with their ordering systems and various other technical problems, including not having enough lines available in my road. These problems overall took a couple of months to resolve.

No products found.

Being a reasonably early adopter of ADSL Max, I also suffered from a number of different ‘teething’ problems. One such problem was caused by the BT network setting all three of my connections to the old 2Mbps throughput rate although the sync speeds were good at 8Mbps. This took a few weeks for support to find out what was going on and resolve. Another problem was caused by the sync rate of one of my lines being set to 6-6.5Mbps due to an earlier line fault during the initial 10 day period (It’s actually the target SNR ratio that’s set – the modem then sets the best speed it can with this SNR target figure). Apparently a BT insider says that the DSLAM (the piece of equipment in the exchange that links many ADSL subscribers to a single high speed ATM line) will eventually set this rate higher but will take several weeks or more to do so (the actual figures and details on how this happens have not been made public as the whole process is going through the patent process apparently). I finally managed to get BT, through Enta support, to manually set this target SNR back to what it should be (lower is better in this case – well, at least to enable high speed syncs) – the line has been syncing at 8Mbps happily since 🙂 It really does pay to keep pushing a resistant support person when you KNOW there’s still a problem!

So anyway, after all these problems, I now have a working ADSL Max MLPP bonded solution – but how’s the performance?

Well, upstream (and my original reason to install this lot was to increase this), I’m getting a steady 2Mbps (250KBps ish) – excellent – just what I wanted so I can upload large files via FTP for my customers quickly 🙂

Downstream is a different matter though and a little disappointing. I get anywhere from 3 to 6.5Mbps depending on the time of day. I’ve tested the throughput of individual lines as well as the 3 line MLPP bond. Sometimes, the 3 line bond performs at the same speed as a single line and at other times, it’s slightly higher – but never as high as I might have hoped for. This is still work-in-progress and I’m continuing to talk to Enta support and the reseller (UKFSN) to see if we can find out why the performance isn’t as expected, still, I’m very happy with the upstream performance which was my main reason for doing this and downstream isn’t exactly slow!

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Note: these figures are actual THROUGHPUT data rates and were measured regularly by a number of methods including the ADSL Guide speed test and real world FTP transfers to several hosted web sites.

So how about costs?  Well, the rough breakdown is as follows:


3 x analogue BT line rental – £11 per line per month (not sure yet if the second and third are charged at £12 or not) + VAT?

3 x Office Max ADSL Max lines (45Gb peak cap each and 300Gb each off-peak) – £25 per month + VAT

Initial Outlay:

Migration of existing line – free

Conversion of Home Highway to Analogue – £50 (IIRC) + VAT?

New line – £99 + VAT?

PC to run router – free (as it was an old machine)

3 x Sangoma S518 ADSL PCI cards – £112 each (no VAT) – includes licence for the bonded router software.

128Mb USB pen drive with write protect switch – £30 (ish)

Note: that although the bonded router software is free, you need a licence for each ADSL PCI card you want to use with it. It is also available from other sources for free but may be an older version. The software is based on GPL software with a high level of customisation/scripts etc.

As I was previously paying £65 + VAT per month for a 2Mbps connection and a fair bit for a Home Highway line, implementing this solution hasn’t cost me a great deal more per month (if you take up front costs out), especially as I’ve gained so much more performance wise.

I hope this has been useful – overall, if you need as much upstream bandwidth as possible, I’d recommend this solution. It’s not for the faint of heart though as there are potentially many problems to be encountered. Hopefully, many of these will not occur though as ADSL Max becomes a more robust and understood product.

Paul Gale can be contacted on – adsl at siliconpixel dot com

Last update on 2024-04-08 / Affiliate links / Images from Amazon Product Advertising API

21 Comments on "ADSL Bonding – How To and Review"

  1. Thanks Paul for this write up . I have 2 adsl lines and this my be a great way to improve my internet connections

  2. Hi, I use Orange in Spain. Do you think this will also work with any other provider, or is there something that the carrier has to do on their end as well?

  3. Hi Guys, just to let you know we provide “True Bonding” with our UBM devices – see for more information.

  4. Hi Guys I have tried the solution from xrio and it does not work there support was poor as well ended up going for a cisco system works well.

  5. @Graeme Sorry to hear you had issues with our equipment. Im surprised you say support was poor as we pride ourselves on responding quickly.

    I’d appreciate your emailing me with details of your issues as I’m keen to maintain quality.

  6. David Barnes | February 16, 2009 at 4:36 pm |

    We have an existing MLPPP (bonded) service.
    However it is no longer performing at it’s best.
    The main problem is inbound bonding seems not to be actually active and we only appear to get the max speed of one line.
    This is in part due to the withdrawall of support for MLPPP at the exchange.
    Upstream still remains reasonable, but the lack of downstream bonding (evident from throughput testing) tends to indicate that our exchange no longer [fully] supports MLPPP.
    On top of this the MLPPP protocol ‘wastes’ some 5-15% of the available bandwidth.
    Further, when not fully working, MLPPP retries and reconnect delays add to the woes.

    What I have found out:
    BT are in the process of changing their core network (Juniper), brought about by 21C BT’s upgrade to an all IP network.
    Here is BT’s official stance:
    “The BT Wholesale IPStream Network does not offer a guarantee that Bonded DSL or DSL lines employing Multi-link Point to Point Protocol (MLPPP) can be supported. Whilst it may be technically possible for a Customer (ISP) to deliver Bonded DSL or MLPPP to an End User, as its not a supported product feature we have no way of guaranteeing support for Customers (ISPs) providing Bonded DSL or MLPPP.”

    Further to this BT have implemented ERX core routers. The new ERX routers use a different architecture and operating system to the existing network equipment, and as such there are issues that are arising which could be impacting a small subset of existing ADSL subscribers with connectivity issues. Neither the new ERX routers, nor the existing network components support the use of Multilink PPP – and this remains unsupported by the network.

    You need to check the 21cn live date for your exchange (samknows) to get an estimate when this service/ability will cease.

    This tends one to think that BT has taken this stance to try and stem the loss of leased line/SDSL business to MLPPP setups.

  7. Chris Needham | April 9, 2009 at 5:50 pm |

    I currently implement bonded mlppp with Nildram and Cisco equipment, however if mlppp ceases after my exchange is upgraded it will cause quite a lot of problems for me.

    The other solution is round robin per packet load balancing, this does not increase download speed on a single download (tcp file transfer). Upload packets get sent across all lines though.

    I recently moved a line to BE, they offer a product with 24 meg up, 2.5 meg down for those lucky enough to have a short line to the exchange, the max I get is 8.5 meg down, 1.2 meg up.

    Looking at the OP’s stats I would think he may be able to get the 2.5 meg upstream speed, and all for just £21.50 a month!

  8. Hi Chris

    You might want to take a look at our solution, Sharedband, we offer bonding at the IP layer using low cost commodity routers. It works well in the 21CN environment. The solution is simple, flexible, and effective. See our website, you can either buy direct from us or from one of our partners.

  9. Jonathan Price | June 14, 2009 at 11:01 am |

    I’ve managed to get dual WAN and triple WAN round robin load balancing working using dd-wrt. Using triple WAN I’m getting more than double my original ADSL download speed, but you only get this if you use a download manager for your downloads, as it creates multiple download tasks which are then split across the three ADSL lines in parallel. Solves my problem though – downloading large files faster.

  10. hi

    I stay in india ( in a village)

    My net speed is 256 kbps

    I like to make live broadcast of our church event.

    I can arrange 4 X 256 kbps

    Can i bond the lines?

    Please guide me


  11. yes you can. try mushroon network’s porcini product.

  12. can i bond 2 gprs modem?

  13. I would be very interested in the gprg / 3g bonding if its possible?

    Anyone have any ideas?

  14. Andrew Ather;ey | February 18, 2010 at 9:58 am |

    Hi does anyone know where to get the bondedcd

    from seams to have disappeared?



  15. intizar57 | May 10, 2010 at 4:48 pm |

    Zeroshell is providing 3g modems link load balancing

  16. I have tried both XRIO and Mushroom bonding devices and I can happily report that the Mushroom devices are in a different league in terms of the functionality, performance and customer support. True Mushroom is a US based company and there can be some timezone issues but as usual we find US customer service much better even though they are several thousand miles away :o)
    The XRIO is flaky at best. Sometimes it works OK but more often than not we have to reboot kit. As for technical support I think XRIO has to be one of the worst companies we have ever dealt with and we deal with a lot of IT companies. They will constantly tell you you need to pay for training and buy their expensive support packages and even when you do this they still have problems solving issues. Quite often they have to log in to the devices and then they usually result in firmware updates.
    In contrast the Mushroom device has only required one reboot in 18 months.
    I don’t care what XRIO say speak to other users and you will find satisfaction levels are very low and most current XRIO users are larger ISP’s that I suspect get huge amounts of support.

  17. Hello ALL,
    I just want to configure snmp on prochini for getting dala collection using OPenNMS.can anyone tell me how to do that and how to configure snmp on prochini to collect data from opennms server?

  18. Hi Paul,

    Great Solution. But, I cant find the bondedcd anywhere. All sites are down. Are you able to put it somewhere on a public site for download?

    Again, thanks for the great tutorial.


  19. Hi Grant.

    Yes – the company that took over the bondedcd ceased trading a while back – mine is still working OK although there’s no support in any shape or form from anyone that I know of.

    I know UKFSN ( used to distribute a version a very long time ago – but don’t know if they still do? Might be worth talking to Jason there if you’re looking for a supported option.

    Otherwise, send me your email address and we can talk further.

    BTW – over the years, the downstream performance increased quite a lot – I got a peak d/l of around 15Mbps but over the last few months that’s dropped to around 7-8 🙁 maybe something to do with the 21cn at the exchange?

  20. quote “over the last few months that’s dropped to around 7-8 smilies/sad.gif”

    Hi Paul

    This is very interesting. I have 4 bonded lines for may years now. First with xifos until they seemed to disappear and stop responding to any customers. I used to get a steady 16Mb – 17Mb from them. I then moved to upstream where I would achieve similar speeds unless it was at busy times. Then when they went under I moved to Entanet via UKFSN. The speed was never as good around 12Mb – 14Mb. About October 2010 I noticed a dramatic drop to about 6Mb – 8Mb. At the same time I noticed we would lose throughput for a few minutes at various times. Even though all the lines would not lose sync. After a few emails to Jason and following all his advise he just stopped replying. I then went direct to Enta who checked all the lines and said everything appeared to be fine and they did not notice any disconnects. They then put a ping monitor in place and did see the lost throughput. Eventually telling me they could not help because I was not using a cisco router. Seems odd we both see the drop in speed around the same time?

    What is also strange is if I set a d/l off it will come down at 790KB – 800KB then if I remove a line and just use 3 it will stay the same. Remove another line and just use 2 again it will stay the same. It does not matter which lines either.

  21. hello where can I download the software Bonded CD image version 2.5. I can not find it

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