[Asterisk-Users] Re: Voicepulse

[Vic Cross]

On Fri, 16 Jan 2004, Bill Hamel wrote:

> Using fqdns in mission critical applications is not a good idea IMHO, it just
> adds another layer of something that can go wrong. 

Or, it just changes the type of things that can go wrong.

In Australia, the recently-introduced number portability infrastructure
for mobile phones means that every call to a mobile number must be routed
through a 'central' directory[1] instead of being sent straight to the
right network based on the number prefix.  Sure, this is one more thing
that can go wrong, but one of the benefits is that you can now switch
between networks without having to change your phone number.

I mention this because it's the same (well, similar) tradeoff between
using DNS and IP addressing.  Will your communications partners
*guarantee* that they will *never* change the IP addresses of their
servers?  If they do change, can you guarantee that you can make all the
configuration changes in all of your servers that communicate with theirs
in a timely-enough fashion to meet service levels?  I'm not suggesting 
that the DNS response to this is entirely flawless, but it does reduce 
administration overhead for adds/moves/changes -- especially between 
different organisations.

Also, using IP address *may* cut you out of load-balancing or disaster 
recovery processes that your partners may make to ensure that you get good 
service from them.

I'm not trying to say that IP addressing is a bad idea.  You just need to 
assess the risks of using either method.

Cheers,
Vic Cross

[1] This is a drastic oversipmlification -- it's actually much worse 
than one single directory as I understand it.