VOIP from Hotel

Whilst on holiday I tried to make a number of SIP VOIP calls via the
hotels WiFi to retrieve calls from my home BT CallMinder.

The hotel had good Wifi and a reasonable Internet connection (better
than I get at home.) but the calls to BT CallMinder always failed after
a few seconds.

I did wonder whether the hotel's Internet connection was deliberately
designed to disrupt VOIP calls in the hope that I would pay to use the
hotels phone.


--
Michael Chare

On Mon, 2012-07-16 at 00:40 +0100, Michael Chare wrote:
> I did wonder whether the hotel's Internet connection was deliberately
> designed to disrupt VOIP calls in the hope that I would pay to use the
> hotels phone.

Did you ask them about it? I often find that strange breakage in hotels
is completely accidental. It's usually outsourced, and when guests
complain they can get their provider to fix things.

Using a VPN also helps to work around issues, fwiw.

On 16/07/2012 11:18, David Woodhouse wrote:
> On Mon, 2012-07-16 at 00:40 +0100, Michael Chare wrote:
>> I did wonder whether the hotel's Internet connection was deliberately
>> designed to disrupt VOIP calls in the hope that I would pay to use the
>> hotels phone.
>
> Did you ask them about it? I often find that strange breakage in hotels
> is completely accidental. It's usually outsourced, and when guests
> complain they can get their provider to fix things.
>
> Using a VPN also helps to work around issues, fwiw.
>

No, perhaps I should have done. I'm not sure what technical questions
one can expect hotel staff to answer.

I did in fact make one short international phone call which did not
appear on my hotel bill!

But this was another hotel where I had to use my Gmail account to send
emails because Gmail allow you to use port 465 instead of the standard
port 25.




--
Michael Chare

On Mon, 2012-07-16 at 12:05 +0100, Michael Chare wrote:
> No, perhaps I should have done. I'm not sure what technical questions
> one can expect hotel staff to answer.

Probably none, but you *can* expect them to put you in touch with (or
pass your complaint/message on to) their provider.

> But this was another hotel where I had to use my Gmail account to send
> emails because Gmail allow you to use port 465 instead of the standard
> port 25.

Port 25 is *not* the standard port, unless you were actually running a
mailer dæmon. Which would probably have been a violation of their T&Cs..

It's quite common for networks to block outbound port 25, and it's a
very sane thing for hotel to do; there's almost no genuine reason for it
to be used.

For submission from a client, the standard is to connect to port 587 "in
the clear" and then enable encryption with the STARTTLS command, just as
you would on port 25. See RFC4409.

Port 465 (and using encryption from the very start of the connection) is
also not a standard. Unfortunately, there was some widely-used software
which was broken, and couldn't be persuaded to conform properly to the
standard — it would try to use encryption from the start, instead of
enabling it with the STARTTLS command, on *any* port except 25.

Since that software was effectively unsupported and its users couldn't
get it fixed, and since its users clung stupidly to it despite the fact
that it was broken in many ways and its author wouldn't support it
properly, the weird non-standard thing on port 465 became common.

It's not needed any more though — even the badly supported softwarein
question *did* eventually get fixed, after a decade or so.