[ILUG] 3G NBS fiasco: Was Help needed with VOIP & Digital Phone

[Michael Watterson]

Alan Ryan wrote:
> Hi Michael,
>
> That's a pretty comprehensive answer - I guess I'll go looking for a wired
> connection.
>
> Thanks,
> Alan
>
> 2009/3/5 Michael Watterson <watty at eircom.net>
>
>   

We haven't even considered the issues on NAT traversal of "3"'s single 
public IP network,
Peer to peer calls via IP if the destination is on 3G (may not be 
connected and very dynamic or few public IPS) and isn't running presence.
3rd Party call provider (e.g. Blueface) phone number based incoming 
calls to your 3G/HSPA

It's not always on either.

Yet mysteriously "3" has won tender for the NBS for which minimum 
connection (before 36:1 SUBSCRIBER (not connection) contention) is 
supposed th be 1Mbps down  and 128k up and support VOIP.

I met Minster Ryan this week and he told me his Experts and "3" have 
assured him it will work. He (nor assistants) couldn't tell me what 
would be monitored, how it would be monitored or what the penalty for 
non-compliance would be as this is all part of confidential Contractual 
arrangements.

3 will  not supply  ethernet NAT/Firewall/Router, but a  USB  dongle.

An ethernet connected solution (WiFi not important as easily added) 
works with ANY OS. (Even TCP/IP on DOS!). Do all USB 3G/HSPA modems work 
with all Linux Distros and Versions?

Dovado, Linksys, Draytek, Netgear, Dlink and others make ethernet 
router/firewall/nat/WiFi boxes that can take various 3G/HSPA modems. In 
a pinch you could put it outside in a plastic box powered by POE.

3's solution is to offer a femto repeater! One box sits at window sill 
(indoor, mains powered) and other is 3G femto base. They are linked by 
WiFi you can't access.
Energy saving Double Glazing blocks 3G/HSPA.

Only 6.5% of outdoor  2km radius  cell can  get  the  fabled 14.4Mbps  
speed.  Average  sector   throughput is about 1Mbps to 2Mbps , shared 
between all users. More than 10 users simultaneously  and average speed 
is less than dialup. If there are  3 or more simultaneous connections, 
then 75% of users on average per cell can't get more than 600Kbps.
.  
http://www.irishwattystuff.com/images/speeddist3g.png

Dark blue line is Sole User in sector moving from 500m (14.4Mbps) to 2km 
from mast (< 1Mbps), outdoor.
Dark purple and light purple are 10 simultaneous and 45 simultaneous 
users evenly spread in sector/cell and the resulting average speed 
depending where you are.
The two flat horizontal lines are 10 simultaneous and 45 simultaneous 
users evenly spread in a similar spectrum of Fixed Wireless Broadband  
sector/cell (FWALA).

If you HAVE to use 3G/HSDPA/HSPA, tell everyone nearby it doesn't work 
so more users won't be added.
Meteor, 3, O2, Vodafone.: The performance differences are due to how 
many people per sector there are. If we assume 50:1 contention can be 
lived with, then you can only have about  100 customers  per  mast,  
hopefully none are  24x7  P2Pers...  You can see why the Cap is low. 
They charging 500x less for the data than phone package (10Gbyte vs 
10Mbyte incoming calls and  10Mbyte outgoing calls per  month).  They 
want to  limit  contention and usage.

The voice is subsidising it as in reality it should be x3 more expensive 
than DSL.
>> Alan Ryan wrote:
>>
>>     
>>> 2009/3/5 Alan Ryan <alan at codecrunchers.ie>
>>>
>>>
>>>
>>>       
>>>> Hi Joerg,
>>>>
>>>>
>>>> The e270 is up and running, pretty reliable.  Used a softphone today, but
>>>> the quality was pretty bad alright.  I could hear them fine, but the
>>>> other
>>>> side said that there was a delay and terrible echo.  Is it the e270 or
>>>> the
>>>> o2 connection that you think the problem might lie with?
>>>>
>>>> Alan
>>>>
>>>>
>>>>         
>>> The problem is Mobile Internet, not specifically O2 or the Modem.
>>>       
>> It has 100ms to 2000ms latency, typically 150ms
>> High Jitter
>> speed varies from 0.050Mbps to  5Mbps +
>> Packet loss can be high or OK.
>>
>> It's inherently unsuitable for VOIP. If more than about 10 people are using
>> your sector it's likely to be poor.
>> It's possible to get more consistent VOIP on 40Kbps dialup!
>>
>>     
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-- 
Mike