Index: asterisk-1.4.17~dfsg/channels/chan_sip.c
===================================================================
--- asterisk-1.4.17~dfsg.orig/channels/chan_sip.c	2009-01-27 23:36:55.000000000 +0100
+++ asterisk-1.4.17~dfsg/channels/chan_sip.c	2009-01-28 00:28:12.000000000 +0100
@@ -8884,6 +8884,23 @@
 	return sip_pvt_ptr;
 }
 
+static const char* next_uri_query_option(const char* query_str) {
+	const char* curr_pos = query_str;
+	const char* result = NULL;
+	while ((curr_pos = strchr(curr_pos, '&')) != NULL) { // Search for option separator
+		if (curr_pos > query_str && *(curr_pos - 1) == '\\') {
+			// Escaped option separator found, try next
+			continue;
+		}else {
+			// There must be one more char (could the '\0')
+			// Return its string position
+			result = ++curr_pos;
+			break;
+		}
+	}
+	return result;
+}
+
 /*! \brief Call transfer support (the REFER method) 
  * 	Extracts Refer headers into pvt dialog structure */
 static int get_refer_info(struct sip_pvt *transferer, struct sip_request *outgoing_req)
@@ -8949,7 +8966,16 @@
 	/* Check for arguments in the refer_to header */
 	if ((ptr = strchr(refer_to, '?'))) { /* Search for arguments */
 		*ptr++ = '\0';
-		if (!strncasecmp(ptr, "REPLACES=", 9)) {
+		// Search for 'replaces=' option
+		char* replaces_option = NULL;
+		do {
+			if (!strncasecmp(ptr, "REPLACES=", 9)) {
+				replaces_option = ptr;
+				break;
+			}
+		}while((ptr = (char*)next_uri_query_option(ptr)) != NULL);
+		
+		if(replaces_option != NULL) {
 			char *to = NULL, *from = NULL;
 
 			/* This is an attended transfer */