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Re: [LUG] Asterisk and getting rid of unwanted calls

 

Hi Paul,

I have some experience running an asterisk box (specifically TrixBox), so 
although I'm no expert by my means, I'll offer my 2 pennies:

Given your hardware I would recommend an Ethernet SIP device like one of 
these: http://www.voipon.co.uk/linksys-analog-adapters-c-2_29.html - this will 
give you flexibility, both in future use - and actual positioning of hardware 
- you can place this adaptor near the phone line and have your PC anywhere on 
the network.

With regards to Sky - I believe the Sky boxes use a dial-up connection for 
their communication. This would be borne out by the fact that they are placed 
after the ADSL microfilter -like a normal telephone. In theory you can route 
Dial-UP through VOIP (as you can fax) but in practice the success of this 
varies best on hardware/network conditions etc (there is a long explanation of 
this, which I'll spare you.) However this is a moot point - a Sky box only 
ever dials out, and only if the line is not busy. As the above mentioned 
adaptors are generally configured to only pick up the line for incoming calls, 
and only can only dial out if the line is free, there should be no line 
collisions. Therefore you can plug your sky box straight into the wall/ADSL 
Microfilter and bypass your Asterisk server. It's worth noting that Sky 
generally only require you to keep the box connected to the line for the 
initial 12 month contract (and you can pay a one-off fee to opt-out of this) - 
but if you upgrade to a subsidised Sky+ or HD box they make you renew this 
clause. Also if it matters to you - (eventually) you won't get box office 
access if you disconnect it from the phone line.

With regards to using the SIP client on your mobile - if you have a strong 
wifi connection it should be possible to achieve good quality calls - however 
if you have an "iffy" connection you may want to experiment with using 
different codecs on the server for the mobile simple client to reduce bandwith 
- unfortunately the less bandwidth heavy codecs tend to eat up more CPU usage 
on the server - so YMMV. I'd have though if you are only doing one call at a 
time you'd be fine.

If you want to experiment without buying any hardware I would suggest you 
install TrixBox CE (free) on your box and get a temporary incoming sip trunk 
from a company such as Gradwell or AQL (and there are plenty of others out 
there). This will give you a local or 0845 etc, number which comes across the 
Internet via SIP or IAX which you can then route to your mobile using SIP over 
wifi - this will let you determine if your hardware is viable before investing 
too much.

In fact you may find this route is all you need - I'm planning to run TrixBox 
in a Virtual Machine on my modest server, and take calls across the Internet 
and route to my mobile handset via WiFi - I have tried this in the past and 
got it to work well, but you do have to be careful about achieving a good 
quality of service on your network (esp your Internet connection) - this for 
me held me back from a complete switch (with people in the house streaming 
music, downloading, watching the iPlayer in HD all at once it would tend to 
choke out the calls). But I have since upgraded my network hardware and can do 
traffic prioritisation - so I'm very much of thinking about switching back.

You should have a lot of fun, and it can also be very practical - for example 
a feature which can be useful for family members in emergencies if they have 
no credit on their mobile is DISA - you could setup an option so that you call 
the house, choose a menu option, enter a password then hang up. The system 
will then call the mobile back, and give the user an outgoing dial-tone where 
they can then enter a number that they wish to call. The system will then 
connect them - incurring no cost on the mobile for that call. Of course to do 
this the server would need two phone-lines (these could be landline, or VOIP) 
- one to call the mobile on, and another to call the destination number - it 
then bridges the call. This also means that your server pays the cost of two 
calls - but sometimes this makes more financial sense, especially if you are a 
business who may have remote agents - they can use their phone, but the 
company absorbs the cost of the calls (and can check to see who they are 
calling ;-) Of course that's quite advanced - but surprisingly simple once you 
get into it.

Hope that helps, I often read posts on here - don't reply very often though!, 
But I thought I could help here - ask me anything else, and I'll do my best.

Cheers,

Charlie Pearce





On Friday 07 May 2010 10:49:11 Paul Hirst wrote:
> I'm getting fed up with silent calls and marketing calls. I've signed of
>  for the relevant services but it's not made a huge difference.
> 
> I'd like to add an asterisk server, connected to my phone line, which can
>  provide a
> 
> Press 1 if you are friends or family
> If this is a marketing call please go away
> If this is an otherwise important call please press 2
> 
> With automatic pass through option 1 if the CallerID matches one in my list
>  of friends and family.
> 
> Currently I have two things plugged into the phone line. A cordless DECT
>  phone (which gives my three cordless phones) and a SKY box.
> 
> I have a Viglen MPC-L (really low power ~400Mhz) machine which I'd like to
>  use  for this. Since it's so small, I don't believe I can plug in a PCI
>  card so I'm looking for suggestions.
> 
> Should I be looking at USB ATA devices or ethernet ones? What's the best
>  deal? How do I know whatever I get can be made to work with Asterisk? It
>  seems most ethernet ones support SIP, does that mean they will work?
> 
> Can I run my SKY box connection through the Asterisk server or do I need to
>  leave it as a normal phone extension? (If I can run it through Asterisk
>  then I could probably disconnect all my phone extensions and just plug my
>  ADSL router and asterisk box (or ethernet ATA) straight into the master
>  socket giving me the best possible ADSL speed).
> 
> Finally, if it's possible, I'd like to get the SIP client I have on my
>  mobile to connect to my Asterisk server so I can phone the phones in the
>  house from anywhere, provided I can find a Wifi point.
> 
> I'm obviously looking to do this on the cheap. Any suggestions and advice
>  would be really appreciated. Thanks!
> ________________________________
> Sophos Plc, The Pentagon, Abingdon Science Park, Abingdon, OX14 3YP, United
>  Kingdom. Company Reg No 2096520. VAT Reg No GB 348 3873 20.
> 

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