SUMMARY OF PATCH STRATEGY

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Single Patch to  /usr/src/asterisk_trunk/include/asterisk/pbx.h:	

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Patches to  /usr/src/asterisk_trunk/channels/chan_sip.c :
	
HUNK 1.
 adds Call_info type to: enum subscription type {...} :

HUNK 2.
defines characteristics of CALL_INFO type to: 
static const struct cfsubscription_types{.....}

HUNK 3.
adds string field to: 
struct sip_pvt{.....}    :

HUNK 4.
adds string field to:
struct sip_peer {.....}    :

HUNK 5.
tests in transmit_state_notify() if AST_EXTENSION_REQLINESEIZE then respond Subscription-State is active:

HUNK 6.
tests in transmit_state_notify() if AST_EXTENSION_REQLINESEIZE then respond Subscription-State is active:

HUNK 7.
in handle_request_invite(...) 
if no matching extension found we check if  this INVITE has Call-Info, ie part of Broadsoft shared call feature,
and patch in destination from peer's notify extension.

HUNK 8.
in handle_request_invite(...) 
the rest of the previous patch
				
HUNK 9.
in handle_request_subscribe(....)
test if not new subscription, but rather Subscribe line-seize event.
If so just acklnowledge it.

HUNK 10.
in handle_request_subscribe(....) if useragent is LINKSYS set to use CALL_INFO to subscribed type

HUNK 11.
When building a peer from configuration (file or realtime static/dynamic) in 
static struct sip_peer *build_peer(....) copy into it the notify_exten