asterisk users - Apr 2005 - Difficulty in configuring Asterisk to ensure that Call Transfers (SIP phone) are properly recorded and billable

I am hoping someone in the * community has come across this problem before.

Problem:

Person SIP Phone A (SIPA)
Person SIP Phone B (SIPB)
SIP Phone C (SIPC PSTN Line)

SIPA calls a billable phone number via SIPC
    exten => _123456/_1XX,1,SetAccount(${ACCOUNTCODE_COMPANYZ})
    exten => _123456/_1XX,2,SetAMAFlags(billing) 
    exten => _123456/_1XX,3,Macro(spa3k_pstn_out,${EXTEN}) 

Then SIPA, whom has generated charges decides to transfer the call the
COMPANYY, and this is where the billing traceable problems begin;

SIPA, transfers the call to SIPB, and the transaction information
appears to be incorrect;

a) SIPA is recorded as connecting with SIPB, and not SIPC.
b) SIPC is then recorded as connecting with SIPB.

Is there a way of ensuring that;
a) SIPA transaction is recorded as SIPA called SIPC.
b) SIPB transaction is recorded as SIPB called SIPC.

A simular scenerio is also happening the other way round. i.e. outside
dialling in via SIPC, SIPA answers, then transfers to SIPB.

Also I need to ensure that the accountcode & billing flags are
correctly set when the call transfer has occurred, but I have not be
sucessful as yet as I am lacking a bit of experience with the inner
workings of configuration.

If there is someone whom has experienced this problem before or
something simular, I would be interested in knowing how you managed to
resolve it.

- Peter

Info:
------
Asterisk:   v1.0.7
SIPA & B: Polycom SoundPoint IP 300
SIPC:        Sipura 3000

I am hoping someone in the * community has come across this problem before.

Problem:

Person SIP Phone A (SIPA)
Person SIP Phone B (SIPB)
SIP Phone C (SIPC PSTN Line)

SIPA calls a billable phone number via SIPC
   exten => _123456/_1XX,1,SetAccount(${ACCOUNTCODE_COMPANYZ})
   exten => _123456/_1XX,2,SetAMAFlags(billing)
   exten => _123456/_1XX,3,Macro(spa3k_pstn_out,${EXTEN})

Then SIPA, whom has generated charges decides to transfer the call the
COMPANYY, and this is where the billing traceable problems begin;

SIPA, transfers the call to SIPB, and the transaction information
appears to be incorrect;

a) SIPA is recorded as connecting with SIPB, and not SIPC.
b) SIPC is then recorded as connecting with SIPB.

Is there a way of ensuring that;
a) SIPA transaction is recorded as SIPA called SIPC.
b) SIPB transaction is recorded as SIPB called SIPC.

A simular scenerio is also happening the other way round. i.e. outside
dialling in via SIPC, SIPA answers, then transfers to SIPB.

Also I need to ensure that the accountcode & billing flags are
correctly set when the call transfer has occurred, but I have not be
sucessful as yet as I am lacking a bit of experience with the inner
workings of configuration.

If there is someone whom has experienced this problem before or
something simular, I would be interested in knowing how you managed to
resolve it.

Info:
------
Asterisk:   v1.0.7
SIPA & B: Polycom SoundPoint IP 300
SIPC:        Sipura 3000