[asterisk-users] How big is *your* dialplan??

[Tim Panton]

On 12 Oct 2006, at 17:16, Douglas Garstang wrote:

>> -----Original Message-----
>> From: Dovid B [mailto:asteriskusers at dovid.net]
>> Sent: Thursday, October 12, 2006 8:14 AM
>> To: Asterisk Users Mailing List - Non-Commercial Discussion
>> Subject: Re: [asterisk-users] How big is *your* dialplan??
>>
>>
>> I worked for some one that installed servers. He has several
>> fully built
>> machines with clean installs ready to go if a client needs a  
>> "loaner".
>
> I guess I'm just not getting it. Sorry. Even if I was an  
> enterprise, not a carrier, I wouldn't want to rely on a server not  
> failing, given that the mtbf between failures on a server is going  
> to be higher than a specialised PBX.

It's a money vs risk thing.
We did an install for a client, they were all for dual-redundant set-up.
I asked them what the maximum acceptable downtime was, and what this  
would
cost them.
The answer was that 4 hours no more than once every 2 years was ok,  
and would
cost them a couple of thousand pounds.

I told them to stick with quality hardware, get a maintenance  
contract and keep a
spare in the cupboard. They have been happy ever since.

Another client insisted they needed minimal downtime and opted for  
clustered
hardware (this was a web/database/telephony system but not asterisk).
In the first 2 years they experienced more downtime than the first  
client.
Both of their failures were complexity related - the first being a  
failing router
that then poisoned the rip-tables of it's failover buddy. The second  
failure
still makes me laugh, they didn't pay the  license on their super- 
duper-journaling NAS
system  which expired taking out the whole cluster :-)

My point being that high up times are hard to attain and simpler is  
often best.

As to MTBF, quality shows, we have just (reluctantly) rebooted a  
decently constructed
database server with an uptime of 850 days to add a disk, it's  
previous reboot
was to add a new tape drive, to my knowledge it has been in service  
for > 5 years.

How long do companies keep their phone systems ? 5 years on average ?

Tim Panton

www.mexuar.com