Index: include/asterisk/cdr.h
===================================================================
--- include/asterisk/cdr.h	(revision 184257)
+++ include/asterisk/cdr.h	(working copy)
@@ -103,6 +103,8 @@
 	/*! Unique Channel Identifier
 	 * 150 = 127 (max systemname) + "-" + 10 (epoch timestamp) + "." + 10 (monotonically incrementing integer) + NULL */
 	char uniqueid[150];
+	/*! CDR Instance per Channel ID. Incremented by a CDR reset if it posts a CDR */
+	int cdrinstance;
 	/*! User field */
 	char userfield[AST_MAX_USER_FIELD];
 
Index: main/cdr.c
===================================================================
--- main/cdr.c	(revision 184257)
+++ main/cdr.c	(working copy)
@@ -270,6 +270,8 @@
 		ast_copy_string(workspace, cdr->accountcode, workspacelen);
 	else if (!strcasecmp(name, "uniqueid"))
 		ast_copy_string(workspace, cdr->uniqueid, workspacelen);
+	else if (!strcasecmp(name, "cdrinstance"))
+		snprintf(workspace, workspacelen, "%d",cdr->cdrinstance);
 	else if (!strcasecmp(name, "userfield"))
 		ast_copy_string(workspace, cdr->userfield, workspacelen);
 	else if ((varbuf = ast_cdr_getvar_internal(cdr, name, recur)))
@@ -284,7 +286,7 @@
 /* readonly cdr variables */
 static	const char *cdr_readonly_vars[] = { "clid", "src", "dst", "dcontext", "channel", "dstchannel",
 				    "lastapp", "lastdata", "start", "answer", "end", "duration",
-				    "billsec", "disposition", "amaflags", "accountcode", "uniqueid",
+				    "billsec", "disposition", "amaflags", "accountcode", "uniqueid", "cdrinstance",
 				    "userfield", NULL };
 /*! Set a CDR channel variable 
 	\note You can't set the CDR variables that belong to the actual CDR record, like "billsec".
@@ -835,6 +837,7 @@
 			ast_copy_string(cdr->dcontext, S_OR(c->macrocontext,c->context), sizeof(cdr->dcontext));
 			/* Unique call identifier */
 			ast_copy_string(cdr->uniqueid, c->uniqueid, sizeof(cdr->uniqueid));
+			cdr->cdrinstance = 0;
 		}
 	}
 	return 0;
@@ -1039,6 +1042,7 @@
 				ast_cdr_end(cdr);
 				if ((dup = ast_cdr_dup(cdr))) {
 					ast_cdr_detach(dup);
+					cdr->cdrinstance++;
 				}
 				ast_set_flag(cdr, AST_CDR_FLAG_POSTED);
 			}
@@ -1063,6 +1067,7 @@
 			cdr->duration = 0;
 			ast_cdr_start(cdr);
 			cdr->disposition = AST_CDR_NULL;
+		ast_log(LOG_DEBUG, "CDR is Reset. Instance is now %d .\n",cdr->cdrinstance);
 		}
 	}
 }