[Asterisk-Users] ADSI phone vs. IP phone

[Andrew Kohlsmith]

> Pretty much no.   The ADSI specification was crippled from the start to
> specificly not compete with PBX offerings.   It has one advantage of
> (very limited) programmability, but a phone like the SNOM has an
> open-source core. It also has the dubious value of being interchangeable
> with a regular analog phone, but that is about it.

I'm looking at ADSI phones simply because I don't have to re-tool my entire 
building; I can use the existing phone network and (I think) get all the 
functionality I need with the (far) cheaper ADSI phones.

My basic ADSI functionality is
- (assisted/consultative and blind) transfers
- voicemail integration (next/prev/forward, MWI, etc.)
- caller ID display
- conference
- hold/park/pickup
- paging
- handsfree
- DND
- global and per-extension speed dial
- muting of DTMF A-D from the far-end

Now I know that not all of these are currently supported with Asterisk's 
ADSI subsystem (call park in particular won't show the "extension" you 
parked the call to on the display), I feel that that is something I can 
either do myself or pay someone to do.  I don't mind paying $300 for 
professional ADSI scripting software so *'s ADSI parser doesn't mean much 
to me.  

The only things I'm really concerned about are the current *insistence* that 
you use # and *8 and bullshit like that instead of making them programmable 
or able to put them in the A-D DTMF tones and be able to put them on soft 
buttons.  I am curious as to whether you can do most of these things after 
a hookflash and how much trouble that will be.  For me it's a showstopper 
that I cannot use * or # in any way I see fit, but I am hoping I can either 
get a patch accepted to free up those (by way of making the digits required 
for call pickup and whatnot programmable) or work around it on my own 
private * system.

> You will not get anything near the functionality and feature set of a SIP
> phone, and it has the further irritation that much of its signalling is
> both in-band and audible.

True, but I don't have to retool my office and install POE switches to use 
ADSI phones, either.  No, I will not put a hub/switch at every desk and 
then use wall-warts for every phone to get around retooling the 
office.  :-)

I was also under the impression that * did a pretty fine job of muting the 
ADSI DTMF tones from the far end.  I know my PT350 and 450 phones mute it 
on their end, anyway.

IP phones are nice, I'll give them that... but they are also a pain in the 
ass if you're upgrading/retrofiting an office, and they also don't play 
well together -- you're more or less stuck using one brand of POE switch 
with one brand of IP phone, or you use wall-warts.  ADSI phones "feel" much 
more phone-like to me, even though IP Phones can do some wild things.

Regards,
Andrew