[asterisk-users] ip phone suggestion for Asia?

[d tbsky]

hi:
   thanks a lot for so many great information. i tried to read the
specs and manuals for all the phones mentioned.
   we use alcatel pbx in most offices. i  surveyed some users to
understand what functions they use most. and i found few people know
how to use 3way-conf or forward.i think if the
function needs two or more keys to operate, then people tend to ignore
it unless he use that function for daily business.
   i conclude the functions we need are all basic functions. but due
to the difference of ip pbx/phones and classic pbx/phones, some of
these functions seem not so "basic" in the ip world:

1. dial out name display. when you dial a number, the phone lcd will
show the corresponding name, so you can realize if it is the correct
number immediately. this needs a corporate directory support, or put
the whole corporate phonebooks to every ip phone. most ip phone has
less than 500 local phonebook entries. this is not enough for us.
    grandstream: has xml phonebook support and can combine with local
phonebooks.
    linksys: has coporate directory but seems only work with linksys
pbx, not asterisk.
    aastra: has xml phonebook
    snom: has ldap and xml phonebook. xml seems for browsing,don't
know if work here.
    other china brand phone: none.

2. transfer. transfer is simple and straightforward in classic pbx.
you just press "transfer" then dial number  and you are on the way of
attended transfer. you press "transfer" again to cancel transfer. you
hangup to complete the attended transfer. if you hangup before the
completion of attended transfer, the  transfer becomes blind transfer
automatically. eventually user didn't notice the  "blind" or
"attended" concept in classic pbx.
   snom: has "transfer on hook". don't know if it can do all what i want.
   others: some china phones almost can do it, but need to press
"hold" to cancel transfer.

3. call back on busy. in alcatel, if  you dial someone and he is on
the phone, you will hear something like "busy, please dial 5 if you
want to request callback". you can dial 5 and you will hear "success,
please hangup". asterisk has several ways and patches to do this. but
i saw some phone can do this locally. i don't know which is better.
    linksys: has this function in spec. don't know how to use.
    snom: has "call completion".
    others: i didn't find this or i miss it.

4. pickup. i think this is easy to emulate "*8" and let asterisk do
it. any better method? every phones can do this emulation.

5. three-way conference, forward. if there are simple (one key) method
to implement these. in alcatel, if the phone if forwarded, when you
pick up the handset you will hear like "forwarded, please press *1 to
cancel". it's easy so everyone can cancel the forward. but it need two
keys to start a forward, so few users know how to forward a number.

please correct me if there are mistakes or missing.
thanks again for your great help!!

Regards,
tbskyd