Page 362 - Asterisk™: The Future of Telephony

‡
offer the five-nines reliability the traditional telecom companies have always touted as
their advantage over VoIP.
Complexity

Open systems require new approaches toward solution design. Just because the hard-
ware and software are cheap doesn’t mean the solution will be. Asterisk does not come
out of the box ready to run; it has to be designed and built, and then maintained. While
the base software is free, and the hardware costs will be based on commodity pricing,
it is fair to say that the configuration costs for a highly customized system will be a
sizeable part of the solution costs—in many cases, because of its high degree of com-
plexity and configurability, more than would be expected with a traditional PBX.
The rule of thumb is generally considered to be something like this: if it can be done
in the dialplan, the system design will be roughly the same as for any similarly featured
traditional PBX. Beyond that, only experience will allow one to accurately estimate the
time required to build a system.
There is much to learn.

Opportunities

Open source telephony creates limitless opportunities. Here are some of the more
compelling ones.

Tailor-made private telecommunications networks
Some people would tell you that price is the key, but we believe that the real reason
Asterisk will succeed is because it is now possible to build a telephone system as one
would a web site: with complete, total customization of each and every facet of the
system. Customers have wanted this for years. Only Asterisk can deliver.

Low barrier to entry
Anyone can contribute to the future of communicating. It is now possible for someone
with an old $200 PC to develop a communications system that has intelligence to rival
the most expensive proprietary systems. Granted, the hardware would not be produc-
tion-ready, but there is no reason the software couldn’t be. This is one of the reasons
why closed systems will have a hard time competing. The sheer number of people who
have access to the required equipment is impossible to equal in a closed shop.

‡ This term refers to 99.999%, which is touted as the reliability of traditional telecom networks. Achieving five
nines requires that service interruptions for an entire year total no more than 5 minutes and 15 seconds. Many
people believe that VoIP will need to achieve this level of reliability before it can be expected to fully replace
the PSTN. Many other people believe that the PSTN doesn’t even come close to five-nines reliability. We
believe that this could have been an excellent term to describe high reliability, but marketing departments
abuse it far too frequently.

334 | Chapter 15: Asterisk: The Future of Telephony