Coms Plc Broadband Review

Coms Plc Broadband Review

ADSL24 to Coms Plc Migration

As a broadband user who lives miles from the nearest telephone exchange with no fibre in the area, my expected download and upload synchronization speeds are never going to be the best with conventional telephone wires. And that’s why, years ago, I signed up with ADSL24 and remained with them for years. They provided an unadulterated broadband connection, and worked with me to optimize my broadband speeds, reduce latency and improve line stability. On moving to them from Tiscali, my average download speeds increased from 0.5Mb/s to an achievable 3Mb/s; with upload speeds almost doubling from 0.5Mb/s to 0.9Mb/s. And more than that, they provided first-class contention and did not engage in stealthy traffic shaping techniques during busy periods: no port blocking and no port throttling. The connection was fast and consistent at all times. And the few problems that I had were dealt with professionally and promptly.

Unfortunately, ADSL24 were purchased by Coms Plc in May 2013 and despite assurances from Coms that my ADSL24 service would not be adversely affected upon migration to them, my download speed dropped by half to 1.5Mb/s and my upload speed dropped back to the former 0.5Mb/s after the switchover. Latency increased and stability issues were a nightmare. The connection kept dropping frequently, resulting in ridiculously low synchronization speeds upon reconnection.

Assurances Made by Coms Plc to ADSL24 Customers | Sent December 2013, Prior to Migration

Coms Plc to ADSL24 Customers

Coms Plc to ADSL24 Customers. Assurances of next generation networks, continuous improvements, and commitment to high quality services.
The promise of no adverse effect on monthly usage limit, or maximum available download speed.
Why is my broadband connection with Coms Plc so terrible then?

 Numerous calls to Coms technical support to get the line synchronization speeds raised to those that I was accustomed to resulted in:

“You live over 7km from the exchange. You should be grateful you’re getting what you have!”

And despite constant pressure from me, the very best speeds I’ve been able to attain through the Coms technical support are nothing like I achieved with ADSL24.

And it gets worse.

Coms Plc Broadband – Stealthy Traffic Shaping & Port Throttling

On Sunday 13th April 2014, I noticed that my broadband connection had been subjected to port-throttling or traffic shaping without being notified that this would happen.

I ran the Glasnost test a number of times throughout the day to determine if this was the case. The ports for bit torrent peer-to-peer communication had been throttled back. The ports for news server connections (nntp) had also been severely restricted.

Coms Plc Glasnost test results. Port throttling.

Coms Plc: Bit torrent peer-to-peer port throttling confirmed with Glasnost


Coms Plc Glasnost test results. NNTP News server port

Coms Plc: Hindrance of control flow transfers on port 119 (nntp) for news servers


I contacted Coms Plc about this and they replied with:

Concerning Coms’ Traffic Management Tools, please see below, Coms’ most recent confirmation on services/time affected;

A basic policy set was deployed to:
Prioritise real-time traffic during peak time (18:00-00:00 weekdays; 10:00-00:00 weekends) e.g.
VoIP, gaming, video etc. to ensure a consistent user experience

::De-prioritise peer-to-peer traffic outside of off-peak (00:00-07:00 daily)

::Ultimately reduce to peer-to-peer traffic during peak time to reduce 95th percentile bandwidth consumption

There are no exceptions to these measures, and the main data protocol that will be affected is peer-to-peer and NNTP.

There has never been, and will be NOT be any blocking of ports.

We are awaiting a final decision to be made at Coms’ concerning this policy.

Our customers can expect communication from Coms once this has been fully implemented as Coms are still trialing these methods.

I take exception to my broadband connection  being used as a test bed to trial these traffic shaping methods, especially when I had received assurances from Coms Plc that my service would not be adversely affected upon migration to them. My speeds have already been halved by their next generation network and by restricting what little bandwidth remains just adds insult to injury. Their broadband is not fit for purpose. I want an ISP, not a http and https provider.

So the original service that I had with ADSL24 has changed despite assurances to the contrary when I was switched to coms.
 I received no notification that Traffic Management Tools / Traffic Shaping techniques were going to be trialled. 
 I was paying for a very good ISP service with ADSL24, now it seems I am paying for a very expensive http and https service.
 Not happy.

Apparently, all ADSL24 customers were sent this, but I never received it.

Upon migration from Adsl24 to Coms, our customers received communication outline the below;

“Are there any changes to my existing contract?

There are no changes to any existing minimum contract term.  If your ADSL24 service was still within a minimum term this will be transferred to your Coms service.  Your Coms service is subject to our standard terms and conditions, a copy of which is available at”

Adsl24 also had a Fair Usage Policy; however I cannot confirm the exact details of how it was implemented across the network.

We apologise that you had not received communication from Coms; however Coms are under no obligation to inform customers of such policy changes.

Once again, we apologise that you feel you are not receiving the level of service you expect from your ISP.

Please let us know if there’s anything we can do for you.

Coms are under no obligation to inform customers of such policy changes.

Hmm, I think a change as significant as this should have been communicated fairly and properly. At least give advanced warning so customers can escape unnecessary suffering by transferring to a capable ISP.

Coms Plc Broadband – No SNR Management Tools

With ADSL24, I had the ability to alter SNR margin myself within my account profile. It is an important feature for someone like me that wants to tweak and experiment with SNR values to get the best performance from a long line. This has been lost with the migration to Coms Plc.

Coms Plc Broadband – In Brief

  • Despite assurances from Coms Plc that my broadband usage would not be affected upon migration from ADSL24, my download and upload speeds  decreased significantly; latency has increased and line stability has declined.
  • Coms Plc technical support take too long to respond to problems. They have not been able to resolve my speed issues and regain my former speeds.
  • Coms Plc employ stealthy Traffic Shaping and Port Throttling techniques to manage their congested network. They prioritize VOIP, gaming and video at the expense of peer-to-peer and news server connections.
  • There is noticeable high congestion at weekends and in the evenings. Even with their Traffic Shaping controls in place, internet browsing speed takes a massive dive.
  • No line controls such as SNR margin selection. You’re at the mercy of their technical support.
  • Clearly, Coms Plc are arrogant in their belief that they can make significant changes to customer agreements without informing them.
  • Only suitable for occasional browsing if you can stomach the lag at weekends and evenings.
  • Expensive and not value for money.

MAC code obtained.

See other complaints about Coms Plc broadband on ISP Reviews.




  1. I had the same experience! I live in Shetland, and had been with ADSL24 for about seven/eight years. After Coms PLC took over, it all went to hell. Youtube and Netflix would barely load. Have moved to Plusnet, and it’s a lot better.

    1. Thanks for the comment, Amy.

      I moved to Pulse8broadband for a similar monthly outlay, no contract and unlimited use. Upon joining, my line was stabilized to regain former speeds. A professional company and fast to respond to customer’s needs. Highly recommended.

  2. Nice write up. I couldn’t have said it better myself. Everything you have experienced with Coms is exactly what I’ve experienced. Currently in progress of migrating to Plusnet.

  3. * Your ISP appears to rate limit your BitTorrent uploads. In our tests, uploads using control flows achieved up to 819 Kbps while uploads using BitTorrent achieved up to 23 Kbps.

    * Your ISP appears to rate limit your BitTorrent downloads. In our tests, downloads using control flows achieved up to 4789 Kbps while downloads using BitTorrent achieved up to 22 Kbps.

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