Unable to raise SIP ALG/MAP-T Issues

[theig]

Well, after a very long series of chats with Sky, it's not good news.

I now get audio on my phone, disabling SIP-ALG solved that issue, but all my other issues remain. The phone disconnects from the VOIP servers for hours every day, so is not useable.

It will be no surprise that Sky are doing their best to blame the other devices in my LAN : hard-wired network switches, NASes and WiFi boosters. The last  use different wifi channels from  the SkyMax so it's unlikely to be wifi interference and in any case wired devices are also affected.

What happens is that the SkyMax router appears to block DNS calls both for  WiFi connections and for hardwired devices such as my desktop and my VOIP phone (that is connected directly to the SkyMax).  Other outgoing traffic - the phone registration to the VOIP provider, for example, are also blocked (server inaccesible error). This happens at random times pretty much every day and can last for hours leaving me, effectively, with no working internet.

I have tried nslookups and pinging the Skybroadband DNS servers and these are reported as inaccessible when I lose the ability to connect to webpages. Whether that indicates a DNS problem or simply that the SkyMax is refusing to send traffic out I don't know.

Windows  reports no internet and troubleshooting reports no DNS.

The Sky phone app cheerfully reports there are no problems, when clearly there are. Of course, I have to use mobile data during these outages since the Sky app needs a working internet connection, which it can't get through the SkyMax.

Sky seem unwilling and unable to help - the classic "Blame the user" approach even though I had none of these issues with either BT or Virgin. The problems started when I moved to Sky just before Xmas.

Can anyone suggest what to try next? The  intervening Xmas break and time spent trying to get Sky to fix things mean I'm now outwith the cooling off period.

[Chrisee]

@theig these issues can be complex first point please post the firmware version your Sky hub is running - log into the web interface at 102.168.0.1 and sign in with the username admin and the wifi password on the label. The issue causing the VOIP issue on the white hubs is so,ved by rolling back a formware release.

Any issues with DNS are almost certainly separate. Sky's DNS system never respond to ping so that is not unexpected. One simple test for DNS issues is to add a public DNS service to a device's network settings I use Google's public DNS at 8.8.8.8 and 8.8.4.4. If that works it is not a routing issue in your network. There is an issue that pops up which is where the server managing your connection does not route DNS traffic correctly powering down for an hour usually fixes Sky has something around 6 million customers they have a lot of server nodes and some do go faulty. Usually you lose the Sky landline at the sametime.

However you mention ethernet switches if they are the managed variety they could be a factor for exampe if the MTU setting is wrong you could get fragmentation issues. Unmanaged switches though should be fine. You also mention NASes depending on set up you could have issues from those so Sky's questions make sense. 

One general point while Sky's hubs are fine for simple domestic networks the lack of confguration makes them a poor choicecfor more complex set ups like your's sounds to be. .Have you considered using a third party router? The Asus range work pretty well on Sky set ups as they have the recommended DHCPv4 Option61 capability. 

[theig]

@Chrisee 

Dear Chrisee,

Many thanks for taking the time to write such a detail reply, unfortunately, I have already tried all of what you suggest except for purchasing a 3rd party NAS.

Distilling down your response it is clear that we agree that the issue is with Sky’s inability to provide a stable DNS connection. “There is an issue that pops up which is where the server managing your connection does not route DNS traffic correctly”; on my connection, this is happening essentially on a daily basis, sometimes several times per day, hence my extreme unhappiness with Sky broadband.

To address your points:

• I cannot easily access the SkyMax web GUI at 192.168.0.1 due to misconfiguration of the interface by Sky.
  1. Edge returns an “address not found” error.
  2. Firefox complains the SkyMax webpage is misconfigured and has an expired security certificate and refuses to let me go any further.
  3. Chrome also complains of an expired security certificate but did, after a few attempts and a “proceed at your own risk warning”,  let me in. I can send  screenshots of the errors if this helps.
• The firmware on the hub was updated last week, I think, to disable SIP/ALG. This was essential to resolve the no audio in or out on my VOIP phone.  
• The SkyMax is a white SR213. The firmware is
  1. DSL Software Version:A2pvfbK048i.d28d
  2. Software Image Name:SR213_7.6p1s2_PROD_sey
• The current VOIP issue I have is that something in Sky’s system “disconnects” all my devices – both hardwired and wifi connected - from the internet due to not being able to find a DNS. The VOIP phone also deregisters from the VOIP provider at the same time.
•  The errors are all variations on “I can’t find the web address, there is a DNS error”. Eventually, usually just before or after midnight, DNS connections are restored. I can then access webpages again and can persuade the phone to register. This behaviour is consistent with your comment “where the server managing your connection does not route DNS traffic correctly “. This is essentially what I have been saying since I started asking about my issues and, to me, confirms that the problem is with Sky, not my LAN devices and settings.
• Since this happens essentially on a daily basis and the disconnect can last for up to 10 hours or/and can happen several times per day, your suggestion of powering down the SkyMax hub each time is not a practicable solution.
• I have tried public DNS servers including Google’s 8.8.8.8, these make no difference which is why I suspect that something in Sky’s system is blocking outbound traffic, it certainly feels that way.
• I appreciate you are much better informed than am I but I find that Sky’s DNS servers do respond to pings – when my internet connection is working. I can send a screenshot if you like.
• I don’t use the Sky phone landline, the charges are ridiculous, so don’t know if this also disconnects but agree with you that this seems likely.
• All my ethernet switches are unmanaged. You say these should fine “Unmanaged switches though should be fine”.
• The NAS is not configured for external access. Many of Sky’s domestic users will run NASes in more complex setups than mine, i.e. with external access; the Sky router should be able to cope with this. If it can’t, then it is not fit for purpose so is Sky’s problem to solve, not mine.
•  I should not have to spend over £100 on a 3rd party router because Sky’s router cannot cope with a simple, internal use only, NAS. In any case, it is not clear to me that a 3rd party router will solve a problem that seems, by your own admission,  most likely to be due to Sky’s system misrouting DNS traffic.

Thank you for your response, even though it gets me no further.

Regards, Jon

[Chrisee]

@theig sorry I dontvthink I can help further.

[theig]

To everyone having these issues, I have just spent the afternoon on the phone to someone at Sky customer service and then to a Sky engineer.

The bottom line is, according to the Sky engineer, Sky's hub is designed NOT to work with 3rd party VOIP services - he implied this is intentional. He also said that it is unreasonable to expect Sky's hub to work with any 3rd party equipment, this includes my laptop.

[Chrisee]

@theig dont know what was said but while it is true that Sky do not support third party apps and the  hubs are designed for domestic use Sky do not design them not to work with business apps and  literally millions of customers use their Sky domestic connections to work from home. Including incidentally including a few thousand Sky employees. Despite not formally offering support Sky have taken action to sort issues with the main business apps including VPNs 

The issue between the white Sky Max hub and some business VPNs is not directly related to the Sky Max hub itself. The problem is related to Sky's use of a system called MAP-T which shares a single IP4 address between up,to 8 customers. This is fine for most applications and has worked well in Sky's operation in Italy for several years. Therefore the introduction of MAP-T was not expected to cause issues in the UK however unfortunately some customers had issues.

Coincidentally these started appearing in the forum while a group of forum superusers including myself were visiting  a Sky facility where we had the opportunity to raise this directly with the network architect responsible for the change . Cutting a long story short while Sky looked into a long term fix a back office system was set up to turn off MAP-T for specific customers which is what the form in the post pinned at the head of the forum does. This sorts almost all customers issues but apparently not yours. Quite why is unclear but I think you are stuck I would expect Sky will release you from contract if you ask. .