[asterisk-users] Teliax Quality of Service

[Trevor G. Hammonds]

From: SIP
Sent: Saturday, August 04, 2007 2:57 PM

>Stephen Bosch wrote:
>> Douglas Garstang wrote:
>>   
>>> I confused by this. Don't ITSP's have redundancy? Don't they have
>>> multiple edge systems for accepting incoming calls? Don't their multiple
>>> edge systems have multiple interfaces, connected to multiple subnets,
>>> via multiple switches? And, don't they have multiple upstream providers?
>>> About the only thing that could go wrong that affects all service like
>>> this would be a badly pushed out software update, affecting all systems?
>>     
>>
>> Don't be confused. The answer to most of your questions is no.
>>
>> Barriers to entry are too small for ITSPs, and there are lots of
>> basement operations masquerading as big carriers.
>>
>> -Stephen-
>>
>>   
>
> There are also lots of big carriers masquerading as big carriers. ;)
>
>
> If the ONLY people who could get into the business were the ones who 
> could, before offering any services to customers, afford to build out 
> multiple edge systems for accepting incoming calls, each with multiple 
> interfaces connected to multiple subnets via multiple switches using 
> multiple upstream providers, you would have ONE single choice for an ITSP.
>
> And AT&T doesn't have that amount of redundancy in their network. 
> Working in the carrier networking business, I can assure you that we've 
> NEVER run across a SINGLE carrier network (not from the largest to the 
> smallest) that has redundancy in ALL aspects (or even MOST aspects) of 
> its network. This is why there are uptime policies that allow a 
> percentage of outages to occur. Triple 9 uptime (Exceedingly rare, but a 
> purported goal -- 99.999%) still allows 15 full hours of downtime a 
> year. And that rarely includes the occasional lost packet or latency.

Your math is incorrect.  FIVE nines (99.999) allows only 5.26 MINUTES of
annual downtime.  Triple nine (99.9%) allows for 8.76 hours of annual
downtime.  Keep in mind that most SLAs do not include "planned" maintenance
in their guaranteed uptime.

> Face it. If you want service that never goes down, you're either able to 
> pay the hundreds of millions to provide your own networks and build out 
> your own redundancy, or you're stuck in the same boat with the rest of 
> us -- be it that you choose a gigantic carrier or a mom 'n' pop ITSP.
>
> N. h

Trevor Hammonds