VoIP fron A&A with Altnet and CGNAT Incoming Calls Only

Hello

I enquired today about porting my landline number from Sky Broadband to A&A Voip because we moved to a Altnet (Lilaconnect) and we are paying for 2 isps at the moment to retain the landline. I was told by A&A voip that because our ISP uses CGNAT there voip will not work. Can I please ask does anyone here use A&A for incoming calls only with a CGNAT enabled ISP and is it working ok with your setup.

I have a Grandstream HT801 ATA and an asus rt-ax82u router.

Thank you in advance.

CGNAT is to be avoided for this sort of reason. Having said that, up to a year ago we had a Grandstream GXP1620 phone running behind CGNAT, which worked to a substantial extent, sometimes dropping out for a few seconds, but workable. Not sure if the problems were due to CGNAT or just shonky connectivity - this was with a wireless ISP. Probably A&A were understandably just avoiding taking on a problematic situation.

Probably the best thing would be to go to a company like Voipfone who do a free months trial and see what happens

Edited by DFScale (Wed 12-Feb-25 21:18:41)

According to their website Lilaconnect offer a public IPv4 address on most of their packages.
Check with them whether that is possible (or alternatively ask whether they support IPv6).
If any of the above fail, you can alsways get an L2TP tunnel from A&A

Thank you for your replies

In reply to essex_man

Yes Lilaconnect offer a Public IPv4 address for £6 per month but my parents signed up for a 12 month discount meaning they are paying £30 per month. If they had there ipv4 public IP (just for voip because they do no gaming they are elderly) then that would mean under Lila's terms the discount would be removed and they would be paying for the full price per month plus the IPv4 Public IP address meaning that there monthly bill will go from £30 a month to over £41 per month just for a public IP address and that does not include the Voip subscription. So this is not an option and it should not be an option of having to pay an extra £11 per month just to be able to use a Voip provider.

Lilaconnect do not supply a IPv6 address.

Thank you for your suggestions but I am finding this all a little overwhelming. Everything I try always seems to hit a brick wall.

Edited by harryhamster (Wed 12-Feb-25 22:09:11)

In reply to a post by harryhamster:

Everything I try always seems to hit a brick wall.

You could still try Voipfone or probably some other suppliers for a month's free trial. See whether it works.

Remember that if you port your existing landline number that will have the effect of ceasing your Sky broadband and phone. As others have suggested you could try something like voiphone but try it as a standalone using the number supplied by them to see if it works before starting the porting process.

Again thank you all for your replies it is most appreciated.

I have tried Voipfone but had problems with the call guardian feature on the bt4600 telephone and there service. They tried to resolve the problem but it was never solved. The problem was that when a caller telephoned the number and the call guardian activated then the person calling needed to announce there name and then press the # key (hashkey) to be connected but it was not connecting and jusr replaying the request to announce there name then after 3 attempts it cut the caller off. Dont know if it was my router at fault or the Grandstream HT801 with voipfone but it did not work for me but not saying it wont work for others.

The BT Phone and Call Guardian worked fine with another voip provider but I had problems with outgoing calls and one way audio with sky landline numbers. So the plan was to use a voip provider to just use for incoming calls only then use mobile phones with unlimited call sims (1 month contracts) for all outgoing calls hence my interest in A&A but after being told that they do not support CGNAT it has put a spanner in the works as I do not want to port my elderly parents landline number to a provider that wil not allow incoming calls because they rely on the landline for hospital and doctors etc.

I understand porting the number over will cease the ISP connection with Sky Broadband. They have been paying Sky Broadband for the past 3 month £55 just for the privilage of keeping there landline number and I want to stop that. They are paying for 2 broadband services and only using one because the landline is tied up with the sky broadband service. They are elderly and cannot keep affording to pay for 2 services just to keep there landline that they have had for 40 years or more active.

This is a very frustraiting situation for myself who is trying to get this sorted out for my parents and my parent who are paying through the nose for a service they are not fully using just to keep and active landline.

Edited by harryhamster (Thu 13-Feb-25 04:46:19)

In reply to a post by essex_man:

If any of the above fail, you can alsways get an L2TP tunnel from A&A

I have looked at the L2TP tunnel from A&A and I have been trying to work out how I would configure that to work with a Grandstream HT801 ATA for the Voip to bypass CGNAT. All I have found is instructions on adding it to an asus router as a VPN but if activated it would act as a active connection for all internt traffic over riding the ISP FTTP connection meaning if I opted for the light 3mps for use with voip then the connection would be limited to 3 mps or am I thinking this wrong?

How would I setup a L2TP service from A&A to use voip and keep the 1gps fttp connection active at the same time for all other internet related activities?

Been doing extensive research in the internet about setting up a L2TP for Voip and there is no information and been getting nowhere.

Thanks in advance

In reply to a post by harryhamster:

I have tried Voipfone but had problems with the call guardian feature on the bt4600 telephone and there service. They tried to resolve the problem but it was never solved. The problem was that when a caller telephoned the number and the call guardian activated then the person calling needed to announce there name and then press the # key (hashkey) to be connected but it was not connecting and jusr replaying the request to announce there name then after 3 attempts it cut the caller off. Dont know if it was my router at fault or the Grandstream HT801 with voipfone but it did not work for me but not saying it wont work for others.

I have just checked and found your earlier thread - sorry it did not register with me.

I have Voipfone, Grandstream HT802 and BT Call guardian 8600, which work OK, apart from a dodgy handset. So a very similar set up to yours. I doubt your router is a player in this as you can establish a call inwards, even if it is not handled correctly by the BT4600 and presumably you can call out too. Your problems are either the finer settings on the ATA or the BT4600 itself.

In reply to a post by harryhamster:

How would I setup a L2TP service from A&A to use voip and keep the 1gps fttp connection active at the same time for all other internet related activities?

There are some ATAs which support L2TP tunnels, so you could replace the Grandstream with such an ATA and plug that into the router.

Alternatively, you could try to get a router that allows "split tunnel", i.e.where only one ethernet port is tunnelled.

Or you could put another box between your existing ATA and your router which terminates the tunnel.

Thank you for your reply DFScale

I think you might be right about the BT4600 being the main problem with Voipfone as I did not try another make of BT phone with call guardian to rule out the BT4600 being the cause of the problem. Might be worth another try with Voipfone with the different setup

Thank you for your reply essex_man

That is interesting to know. I did some research on the internet after reading your reply and there are ATS's that do support L2TP Tunnels and certainly something to look into

Options are now looking a little better than they did 24 hours ago and I was in a bit of a fluster and completely confused but after 24 hours and requesting information from my ISP about the provisioning of a Public IP address (If required) I am feeling a little more confident on getting the Voip problem I am having resolved.

In reply to a post by harryhamster:

Yes Lilaconnect offer a Public IPv4 address for £6 per month but my parents signed up for a 12 month discount meaning they are paying £30 per month. If they had there ipv4 public IP (just for voip because they do no gaming they are elderly) then that would mean under Lila's terms the discount would be removed and they would be paying for the full price per month plus the IPv4 Public IP address meaning that there monthly bill will go from £30 a month to over £41 per month just for a public IP address and that does not include the Voip subscription. So this is not an option and it should not be an option of having to pay an extra £11 per month just to be able to use a Voip provider.

I am replying and quoting myself to inform that the information I posted was not correct and it was wrong. I got the impression that Lilaconnect if requested to have a Public IP added to the customers account would affect the promotion that the customer signed up under. I got this impression from a reply they made to a review on trust pilot where the customer changed there package from the origional package they signed up for so invalidating there promotion offer. I would like to add that after contacting Lilaconnect today that if a customer wants to have a Public IP added to there account they can do so and it will NOT affect any promotional offer they signed up for it will just be an extra £6 a month on there current billing.

Also if the Public IP is not required it can be removed from the customers account.

Just thought I would post that so not to give false information and to correct my misunderstanding. If I am still having problems with voip then the extra £6 a month maybe worth the investment. I would like to give credit to Lilaconnect for the prompt support and clear advice and information.

Grafting old world analogue tech (Call Guardian / analogue handsets even ATAs are often a bit crusty with some firmwares) to new world tech IP-based telephony is unfortunately not always going to be smooth sailing.

There’s a lot of ‘moving parts’ some of which you have no real control over -
I would suggest you speak to the folks at trueCall as they may be able to help if you decide to ultimately utilise one of their standalone devices, rather than through the BT handset / base.

https://www.truecall.co.uk/category-s/116.htm

Saying that they say they don’t recommend using their units with VoIP services - they may need to catch up their FAQ or perhaps they have a more recent firmware update on their standalone devices which could help…

You might want to get a public IPv4 address initially, while you look into other options. £6 per month sounds a bit steep, I had public (sticky) IPv4 from Metronet and later from Plusnet for a one off £5, but it seems that those days are gone.
At least that would give you plenty of time to work on a L2TP solution and then switch when you got that working reliably. L2TP Business Light from A&A costs you £2.40 per month, so only some saving over public IP

There are some "free" L2TP providers, no idea whether they are any good/reliable

I've got A&A VOIP, HT801 and BT 2600 Truecall. When I saw your previous thread about unknown callers not being able to get through I made a test and it seemed to work for me. DFScale doesn't have issues either when using VOIPfone.

Where did you get the HT801 from? VOIPfone? Did it come pre-configured? What instructions did you use to configure it? I'm running version 1.0.57.1 on the HT801. It is a V1 HT801 but there are V2 HT801 available.

The VOIPfone HT setup looks a little basic https://www.voipfone.co.uk/support/hardware/adapters... compared to https://forums.thinkbroadband.com/voip/4729179-aa-vo...

@DFScale, how did you configure the HT801?

In reply to a post by BarkingMad:

@DFScale, how did you configure the HT801?

It's actually an 802 - same difference, though.

I just found the default IP address, gave my PC an IP address on the same subnet and made reasonable assumptions about settings, tried it and addressed the bits which didn't work. I got my tones from I think ferretuk's post or a similar post. I can post information on particular settings, if you like, but I don't have a record and I am not inclined to post everything

I only have Grandstream devices, because of price and I don't know if other internet phone devices on the FXS end are similar, but I think that while the flexibility to imitate any kind of line is amazing, [including such curiosities as New Zealand and Sweden pulse dialling] the setup process is a mess. It really requires a single set up menu for all of the phone line options, where you select a country and the whole phone setup is populated with correct or workable settings, after which you can trim things if you so desire.

Thanks @DFScale,

Given you and I don't appear to have the same issue - and we're using different BT handsets and different VOIP providers it may be a setting in the HT801 that is not correct. There are several which mention BT-SIN. It could be a problem with the handsets as others have suggested.

The GUI on the HT8xx V2 is more modern and is a little more organised.

Thanks for the option to post specific config.

Lets see how the OP has configured the HT.

Although the CGNAT may still be an issue even if VOIPfone can be made to work with their HT and BT handset.

Thinking aloud. If I remember correctly, most UK mobile networks use CGNAT - so how do softphone apps work with VOIP? Or does CGNAT just make it more likely that problems will occur?

Edited by BarkingMad (Fri 14-Feb-25 12:53:22)

In reply to a post by BarkingMad:

Although the CGNAT may still be an issue even if VOIPfone can be made to work with their HT and BT handset.

Thinking aloud. If I remember correctly, most UK mobile networks use CGNAT - so how do softphone apps work with VOIP? Or does CGNAT just make it more likely that problems will occur?

I am not sure about NAT or CGNAT being a real issue. My 2 instances of VoIP devices have been configured behind Customer NAT and I have had to do nothing to accommodate for that. And I don't think another layer of NAT should introduce a problem of principle. My own experience of CGNAT was bad and I think it was due to a somewhat overloaded network and probably the Network Address Translators are potentially a bottleneck, particularly on the scale of an ISP. I was very much aware of the warnings about VoIP and NAT, but they were not an issue for me. I think that [was it A&A?] not wanting to offer service over another networks CGNAT is because they have no control over the quality of service for which they might be blamed.

In reply to a post by DFScale:

I think that [was it A&A?] not wanting to offer service over another networks CGNAT is because they have no control over the quality of service for which they might be blamed.

A&A hate any NAT, they don't even seem to comment on CGNAT which I can see Rev K going off on one of his rants about.

SIP and NAT were never best friends, but with STUN it works very well, and over a cellular connection where 99% of them are NAT and there is no routed IP available.

Those newer ISPs forced into CGNAT for IPv4 really should offer routed IPv6 at the same time. To not do so is crazy.

In reply to a post by jchamier:

Those newer ISPs forced into CGNAT for IPv4 really should offer routed IPv6 at the same time. To not do so is crazy.

I agree. My ISP offers both a fixed IP [v4] and IPv6. Having used IPv6 for about a year now, I think I would actually give up the fixed IP [v4] and accept dynamic IP [v4] and even go to CGNAT [v4] in 5 years time if it were on a pathway to eliminating IPv4 from the public internet over 10 years.

I have just checked through the devices on my network and they are all IPv6 capable to varying degrees and I think my only requirement for IPv4 access to the public network right now would be to access the external sites which are IPv4 only.

Edited by DFScale (Fri 14-Feb-25 20:58:30)

If we can have ubiquitous CLAT (464XLAT) available that moves v4 further towards a transition to a legacy service that is implemented over v6.

OSes for mobiles have implemented it for some years but the situation for desktops is more mixed.

In reply to a post by prlzx:

If we can have ubiquitous CLAT (464XLAT) available that moves v4 further towards a transition to a legacy service that is implemented over v6.

Aye, but.

Essentially this requires that both ends have 464XLAT, when they could just go dual stack. Which is what customers with IPv6 are doing.

ISP's are spending squillions trying to buy IPv4 addresses, which exacerbates the problem, because now they have a revenue stream which will disappear and the addresses become a redundant asset if there is no longer a need for IPv4. There is now a financial incentive to keep IPv4 going

Have Altnet (wefibre), with CGNAT incoming calls from either A&A or Sipgate are very flaky and often dont work.
Got a static IP and all works well .
Calls to a mobile using Acrobits Softphone worked all the time .

What was terminating the VoIP calls when not using a soft phone?

If it was/is an ATA that’s typically your problem. Stuff like NAT traversal and media stream handling on many implementations is sub par.

A a good softphone client like acrobits will work seamlessly on almost any connection by comparison as their implementations are just superior.

I don't know if the OP is still looking for a solution.

If the objective is to find out if SIP signalling and the media (RTP) traffic works reliably over the Lilaconnect network and it's CGNAT gateway why not create a couple of accounts with a VOIP provider which offers free IP to IP calls between subscribers on their system. Then make test calls between those accounts at different times of the day to check if calls get through reliably and there are no audio dropouts or disconnections. For a valid test, of course, you use a seperate Internet connection for one of the accounts so that all the traffic does traverse the Internet.

If it works OK with one VOIP provider then there is no reason why it would not work with A&A if configured well. It might be necessary to configure the ATA to make sure there are frequent enough keepalive packets sent to prevent NAT table timeouts. CGNAT gateways are said to have shorter NAT timouts than customer routers.

I use VOIP over a 4G mobile Internet connection and an ATA. The traffic goes via a CGNAT gateway in the mobile providers network. I never experience any problems (dropouts or missed calls etc.) Maybe I am lucky.

For simple VOIP IP to IP calls (not going over the PSTN), e.g. for communicating with friends and family, I find callcentric to be a good choice. Each subscriber gets an 11 digit number starting 1777 and IP to IP calls between subscribers are free. It is a non-U.K provider (New York), but with VOIP, only the SIP signalling goes via the provider's server. For IP to IP calls the media RTP traffic goes directly between the subscribers. So using a provider on another continent does not increase the audio latency of IP to IP calls.

Other, U.K. based providers might offer a similar feature but most these days want a monthly subscription fee.

Edited by gc001 (Thu 13-Mar-25 20:29:50)