[Asterisk-Users] IP Phone recommendations?

[Jim Van Meggelen]

asterisk-users-bounces at lists.digium.com wrote:
> Hey gang,
>   I'm looking at escaping from a Nortel Meridian CISC system
> to Asterisk/Digium/SIP phones.  I'm currently in the testing
> and proof of concept phase.  I'm going to need a SIP phone
> and don't want to re-purchase and have "orphans" around.

I've got a few different IP phones in my lab (including a C7960), I'm
currently loving my Polycom 300 - a solid phone for the price, and
everyone says the 500 and 600 are even better. I think I'll be going
with Polycom for my customers until the next best thing comes along.

I looked at the Snom phones when I was at Astricon, and while they may
be technically great, the problem I had with them is that they are not
weighted properly. If you've ever yanked your phone off the desk you'll
understand the need for a proper ballast. The handsets feel cheap too,
because they're too lightweight. Still, from everything I've read you'll
certainly want to try one out. Also, the Snom 220 seems to be the best
bet as a reception phone, especially if you want a busy lamp field on
your swithboard.

The Cisco phones are great, but it's hard to stomach paying an extra
$100-$300 for that little drawing of the Golden Gate Bridge they put on
all their products.

One of the exciting things about standards-based telephony is that you
can mix and match your phones. It's the same as analog sets; the agony
is in the sheer number of choices available.

> We currently run Nortel 7310 phones and they work great.
> I'm sort of overwhelmed by all of the different IP phones.  I
> was hoping some folks would share what they have found. My
> primary goal is to replicate the 7310's features and to allow
> room for growth in the future with telephony applications.

One of the big differences between the Norstar and the Asterisk is that
the Norstar is a key system, the Asterisk is a PBX. If you completely
replace the Norstar your users will will no longer have access to line
status on their phones; that is all handled behind the scenes. Also, you
will not get busy lamp field, which means you won't be able to monitor
who is on the phone (there are ways of doing this in Asterisk, but it's
not as intuitive to implement). Finally, the Norstar has hundreds of
easy to use features; each one you'll want to keep will need to be
carefully hand-crafted in the dial plan.

> Our primary driver is configurability and features that we
> can get in Asterisk, that we can get without a lot of money
> from Nortel.

Nortel sure has fallen behind. Even the VoIP stuff they have does not
work well, and is barely standards-compliant (if at all).

> Namely-
> Voicemail, telecommuting workers on the pbx, better call
> handling, better automation. I'd like to be able to integrate
> smart features like directory and call handling to the
> handset, but I'll freely admit I'm just starting out. My
> initial goal is to just to get onto Asterisk and get it
> working. I'll worry about cool stuff later.

I think you'll be wise to leave the Nortel KSU in place for a bit. That
way you can introduce new features to the users without them also having
to learn new phones. There are challenges either way.
 
> Our integration and migration plan is as follows:  If anyone
> has some suggestions or pointers I'd love to hear them.
> 
> 1. Test and evaluate Asterisk with TDM400 with 1 FXO/FSO port
> each. 2. Configure Asterisk to be the primary PBX and slave
> the Nortel Meridian system to it using a second TDM400.  This
> avoids immediate replacement of all handsets.  Will allow
> immediate access to features such as Voicemail. 3. Overtime,
> upgrade desk phones to IP phones.  When all phones are
> replaced, decommission Nortel and sell on Ebay.  :)

Are you using calling line ID? The problem here is that you have two
systems that will each need to wait two rings before answering. The
Asterisk will need two rings to get the caller ID, and then it'll take
two more to pass the same CLID on to the Norstar.

[PSTN]==(2 rings for CLID)==[Asterisk]==(2 rings for CLID)==[Nor*]

Make sure you put an autoattendant in the middle, to ensure your callers
don't have to wait too many rings before some indication that there's a
system at the other end. 

Also, there is some danger of echo if you put the Asterisk in the
middle. You'll want to be patient with this, as it may take a bit of
tweaking to sort out. 
IMPORTANT: Make sure your Asterisk and Nortel are grounded to the same
point. Best way to achieve this easily will be to plug them into the
same electrical outlet. You do NOT want voltage potentials on the analog
loop between the * and Nor*, believe me.

The fact is, analog is a technology that really doesn't lend itself well
to integration. It can be made to work, but callers and users will have
to deal with a lot of extra rings. Also, transfers and the like will
involve hookswitch flashes and such. I'm not saying avoid it, just be
aware of the need to manage user expectations. One possible way to
handle this would be to configure the system so that the Norstar sees
the Asterisk as a sort of Centrex service. This would require dedicating
an analog line for any set you wished to integrate. 

[Asterisk]       [Norstar]
FXS(ZAP/1)---L001(R&A)-x21
FXS(ZAP/2)---L002(R&A)-x22
FXS(ZAP/3)---L003(R&A)-x23
FXS(ZAP/4)---L004(R&A)-x24
FXS(ZAP/5)---L005(R&A)-x25
FXS(ZAP/6)---L006(R&A)-x26
FXS(ZAP/7)---L007(R&A)-x27
FXS(ZAP/8)---L008(R&A)-x28

The Norstar offers a lot of Centrex integration features, so your
voicemail/message waiting and such would work well. Also, the Asterisk
would then easily be able to handle the different users on the Norstar,
as it would have a dedicated line for each of them. The only problem
there would be the cost of the integration hardware, and the fact that
your CICS can only grow to a maximum of 8 analog lines.

Another possibliity would be to use BRI to integrate the two. This,
however, will require a BRI card in the CICS (as well as a services
cartridge), as well as BRI hardware for the Asterisk. Not to mention
that BRI is a pain in the butt to configure. Still, one you've got it
working you'd have full ISDN integration between the boxes, which'd be
technically superior to analog. It really depends on what sort of a
science project you want this to become.

> Cold turkey option is to spend the extra $ and buy the
> handsets upfront and just ditch nortel without a transition period.

It'll be easier technically, but for the users this might be a bit more
painful.

> We currently have 4 pbx lines and 1 dedicated fax/credit card line.
> We have 10 handsets. 

Well, your Asterisk will certainly put you in an excellent position to
grow.

Cheers,

Jim.




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