Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 168829)
+++ channels/chan_sip.c	(working copy)
@@ -4633,6 +4633,8 @@
  */
 static int create_addr_from_peer(struct sip_pvt *dialog, struct sip_peer *peer)
 {
+	struct ast_variable *p_cur, *d_cur = NULL;
+
 	/* this checks that the dialog is contacting the peer on a valid
 	 * transport type based on the peers transport configuration,
 	 * otherwise, this function bails out */
@@ -4761,6 +4763,13 @@
 	if (peer->call_limit)
 		ast_set_flag(&dialog->flags[0], SIP_CALL_LIMIT);
 	
+	for (p_cur = peer->chanvars; p_cur; p_cur = p_cur->next) {
+		struct ast_variable *d_new = ast_variable_new(p_cur->name, p_cur->value, "");
+		d_new->next = d_cur;
+		d_cur = d_new;
+	}
+	dialog->chanvars = d_cur;
+
 	return 0;
 }
 
@@ -6202,8 +6211,11 @@
 		pbx_builtin_setvar_helper(tmp, "_T38CALL", "1");
 
 	/* Set channel variables for this call from configuration */
-	for (v = i->chanvars ; v ; v = v->next)
-		pbx_builtin_setvar_helper(tmp, v->name, v->value);
+	for (v = i->chanvars ; v ; v = v->next) {
+		char valuebuf[1024];
+		ast_get_encoded_str(v->value, valuebuf, sizeof(valuebuf));
+		pbx_builtin_setvar_helper(tmp, v->name, valuebuf);
+	}
 
 	if (state != AST_STATE_DOWN && ast_pbx_start(tmp)) {
 		ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
@@ -16098,9 +16110,11 @@
 		struct ast_variable *v;
 	
 		chanvar = strsep(&chanvar, "]");
-		for (v = peer->chanvars ; v ; v = v->next)
-			if (!strcasecmp(v->name, chanvar))
+		for (v = peer->chanvars ; v ; v = v->next) {
+			if (!strcasecmp(v->name, chanvar)) {
 				ast_copy_string(buf, v->value, len);
+			}
+		}
 	} else  if (!strncasecmp(colname, "codec[", 6)) {
 		char *codecnum;
 		int codec = 0;
@@ -22283,7 +22297,8 @@
 	const char *srvlookup = NULL;
 	static int deprecation_warning = 1;
 	struct ast_str *fullcontact = ast_str_alloca(512);
-	
+	int chanvar_no = 0;
+
 	if (!realtime || ast_test_flag(&global_flags[1], SIP_PAGE2_RTCACHEFRIENDS)) {
 		/* Note we do NOT use find_peer here, to avoid realtime recursion */
 		/* We also use a case-sensitive comparison (unlike find_peer) so
@@ -22583,6 +22598,13 @@
 			}
 		} else if (!strcasecmp(v->name, "setvar")) {
 			peer->chanvars = add_var(v->value, peer->chanvars);
+		} else if (!strcasecmp(v->name, "header")) {
+			char varbuf[30];
+			struct ast_variable *newvar;
+			snprintf(varbuf, sizeof(varbuf), "__SIPADDHEADER%.2d", ++chanvar_no);
+			newvar = ast_variable_new(varbuf, v->value, "");
+			newvar->next = peer->chanvars;
+			peer->chanvars = newvar;
 		} else if (!strcasecmp(v->name, "qualify")) {
 			if (!strcasecmp(v->value, "no")) {
 				peer->maxms = 0;
Index: configs/sip.conf.sample
===================================================================
--- configs/sip.conf.sample	(revision 168829)
+++ configs/sip.conf.sample	(working copy)
@@ -58,6 +58,9 @@
 ;
 ; You can still set limits per device in sip.conf or in a database by using 
 ; "setvar" to set variables that can be used in the dialplan for various limits.
+;
+; You can also preset SIP headers to be added to outgoing invites by setting
+; "header" to those items, e.g. header=X-Something: something-else
 
 [general]
 context=default                 ; Default context for incoming calls
@@ -782,6 +785,7 @@
 ; useclientcode
 ; accountcode
 ; setvar
+; header
 ; callerid
 ; amaflags
 ; callcounter