[Asterisk-Users] sharing a line w/multiple extensions

[Rich Adamson]

> >> phones.  When someone picks up (don't know how I can detect this), it 
> >> could transfer both parties to a meetme room.  When additional 
> >> extensions pickup, they go to the meetme room.  When everyone hangs 
> >> up, the call ends.  Can this be done?
> >
> > Probably, but it would take some very creative dialplan programming 
> > and an external application to transfer the parties into a meetme 
> > room. You will not get 'pickup' behavior on the SIP phones regardless, 
> > they will have to press a speed dial button which would attempt to 
> > join the meetme.
> >
> > In other words: you can get there, but it will _not_ behave like a key 
> > system, and people will expect it to, so they will be frustrated when 
> > it doesn't. We've been down this road many times before, and many 
> > Asterisk installations have been taken out because the installers 
> > thought they could achieve key system behavior (or retrain the users) 
> > but failed. If you want to try, feel free... I'm only telling you what 
> > has happened before :-)
>
> Thanks.  That's very helpful because being new to Asterisk, I don't know 
> the history of what people have attempted to use Asterisk for.  It's 
> unfortunate that there's no way to do it because it sounds like others 
> are looking for this same functionality.  I wonder what it would take to 
> implement this in Asterisk natively.  Does Digium take feature 
> requests?  Certainly, this would have appeal for residential systems.

Just a couple of comments on the subject of key systems verses pbx's....

The traditional pbx (from years ago) implemented exactly what Kevin
mentioned above. Just about every company that deployed a pbx back then 
also had several key systems attached to their pbx. The key systems were
typically limited to executives and their assistants (secretaries
back then) primarily due to the additional cost of the older key systems.

The traditional pbx vendors (back then) would "always" use the same words
that Kevin used, emphasizing the differences between key systems and
pbx's. However, many of the pbx manufacturers finally realized they
were loosing revenue due to those limitations, and began implementing
key-system-type functions in their pbx's. They were not trying to address
the key system market, but rather make their pbx products more valuable
from a user's perspective. Those that are influencing or controlling the 
direction of asterisk haven't learned that lesson as yet, partially because 
of the lack of functionality in the sip phones themselves and partially 
because asterisk is being developed through the open source community 
(limited development resources and no published long term plan).

Those individuals that have worked towards developing the sip rfc standards
have recognized some of the key system vs pbx needs, and have added to
the sip standards. However, it takes a while for the sip phone manufacturers
(and voip pbx manufacturers) to implement those standards, and in some 
cases, the manufacturers purposefully leave out certain functions in their 
sip products to protect their investments in proprietary products.

It certainly is not difficult to visualize how voip switching products
(such as asterisk or any of the commercial products) could be oriented
towards being a "switch" and address the needs of key systems, pbx's,
and central office switching in the same basic product. All of the same 
functions are required in each case. Asterisk will get there, it will just
take a little longer since there isn't any published long term plan to
influence the short term development. (No offense intended to any asterisk
individual or group; just the nature of most open source development.)

I can also assure you that several large companies (most of those company
names likely wouldn't be recognized by many of the readers here) are 
watching the asterisk development closely, and likely are in fear of various 
open source products negatively impacting their core business. They will
adjust their product development (and plans) in an effort to remain one
(or more) steps ahead from a "marketing & sales" perspective.