diff -Nurp trunk/include/asterisk/srv.h patched/include/asterisk/srv.h
--- trunk/include/asterisk/srv.h	2007-11-05 19:53:13.000000000 -0700
+++ patched/include/asterisk/srv.h	2009-03-26 22:40:15.000000000 -0600
@@ -23,6 +23,8 @@
 #ifndef _ASTERISK_SRV_H
 #define _ASTERISK_SRV_H
 
+#include "asterisk/linkedlists.h"
+
 /*!
   \file srv.h
   \brief Support for DNS SRV records, used in to locate SIP services.
@@ -31,6 +33,26 @@
 	no provisions for retrying or failover between records.
 */
 
+struct srv_entry {
+	unsigned short priority;
+	unsigned short weight;
+	unsigned short port;
+	unsigned int weight_sum;
+	AST_LIST_ENTRY(srv_entry) list;
+	char host[1];
+};
+
+
+struct srv_context {
+	unsigned int have_weights:1;
+	AST_LIST_HEAD_NOLOCK(srv_entries, srv_entry) entries;
+};
+
+/*!	\param	context The context in which to store the result
+	\param	service The service name to look up
+*/
+extern int ast_srv_lookup(struct srv_context *context, const char *service);
+
 /*! Lookup entry in SRV records Returns 1 if found, 0 if not found, -1 on hangup 
 	Only do SRV record lookup if you get a domain without a port. If you get a port #, it's a DNS host name.
 */
diff -Nurp trunk/main/srv.c patched/main/srv.c
--- trunk/main/srv.c	2009-01-12 16:13:13.000000000 -0700
+++ patched/main/srv.c	2009-03-26 22:23:49.000000000 -0600
@@ -53,20 +53,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revisi
 #define T_SRV 33
 #endif
 
-struct srv_entry {
-	unsigned short priority;
-	unsigned short weight;
-	unsigned short port;
-	unsigned int weight_sum;
-	AST_LIST_ENTRY(srv_entry) list;
-	char host[1];
-};
-
-struct srv_context {
-	unsigned int have_weights:1;
-	AST_LIST_HEAD_NOLOCK(srv_entries, srv_entry) entries;
-};
-
 static int parse_srv(unsigned char *answer, int len, unsigned char *msg, struct srv_entry **result)
 {
 	struct srv {
@@ -197,6 +183,18 @@ static void process_weights(struct srv_c
 	AST_LIST_APPEND_LIST(&context->entries, &newlist, list);
 }
 
+int ast_srv_lookup(struct srv_context *context, const char *service)
+{
+	int ret;
+
+	ret = ast_search_dns(context, service, C_IN, T_SRV, srv_callback);
+
+	if (context->have_weights)
+		process_weights(context);
+
+	return ret;
+}
+
 int ast_get_srv(struct ast_channel *chan, char *host, int hostlen, int *port, const char *service)
 {
 	struct srv_context context = { .entries = AST_LIST_HEAD_NOLOCK_INIT_VALUE };
@@ -206,10 +204,7 @@ int ast_get_srv(struct ast_channel *chan
 	if (chan && ast_autoservice_start(chan) < 0)
 		return -1;
 
-	ret = ast_search_dns(&context, service, C_IN, T_SRV, srv_callback);
-
-	if (context.have_weights)
-		process_weights(&context);
+	ret = ast_srv_lookup(&context, service);
 
 	if (chan)
 		ret |= ast_autoservice_stop(chan);
diff -Nurp trunk/res/res_agi.c patched/res/res_agi.c
--- trunk/res/res_agi.c	2009-03-18 08:32:47.000000000 -0600
+++ patched/res/res_agi.c	2009-03-27 15:00:48.000000000 -0600
@@ -57,10 +57,12 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revisi
 #include "asterisk/speech.h"
 #include "asterisk/manager.h"
 #include "asterisk/features.h"
+#include "asterisk/srv.h"
 
 #define MAX_ARGS 128
 #define AGI_NANDFS_RETRY 3
 #define AGI_BUF_LEN 2048
+#define SRV_PREFIX "_agi._tcp."
 
 static char *app = "AGI";
 
@@ -523,7 +525,7 @@ static enum agi_result launch_netscript(
 	struct hostent *hp;
 	struct ast_hostent ahp;
 
-	/* agiusl is "agi://host.domain[:port][/script/name]" */
+	/* agiurl is "agi://host.domain[:port][/script/name]" */
 	host = ast_strdupa(agiurl + 6);	/* Remove agi:// */
 	/* Strip off any script name */
 	if ((c = strchr(host, '/'))) {
@@ -602,6 +604,81 @@ static enum agi_result launch_netscript(
 	return AGI_RESULT_SUCCESS_FAST;
 }
 
+/*!
+ * \internal
+ * \brief The HA fastagi handler.
+ * \param agiurl The request URL as passed to Agi() in the dial plan
+ * \param argv The parameters after the URL passed to Agi() in the dial plan
+ * \param fds
+ * \param efd enhanced AGI flag
+ * \param opid
+ *
+ * Uses SRV lookups to try to connect to a list of AGI servers. The hostname in
+ * the URI is prefixed with _agi._tcp. prior to the DNS resolution. For
+ * example, if you specify the URI \a hagi://agi.example.com/foo.agi the DNS
+ * query would be for \a _agi._tcp.agi.example.com and you'll need to make sure
+ * this resolves.
+ *
+ * This function parses the URI, resolves the SRV service name, forms new URIs
+ * with the results of the DNS lookup, and then calls launch_netscript on the
+ * new URIs until one succeeds.
+ *
+ * \return the result of the AGI operation.
+ */
+static enum agi_result launch_ha_netscript(char *agiurl, char *argv[], int *fds, int *efd, int *opid)
+{
+	char *host, *c, *script = "";
+	enum agi_result result = AGI_RESULT_FAILURE;
+	struct srv_context context = { .entries = AST_LIST_HEAD_NOLOCK_INIT_VALUE };
+	struct srv_entry *current;
+	int srv_ret;
+	char service[256];
+	char resolved_uri[1024];
+
+	if (efd) {
+		ast_log(LOG_WARNING, "AGI URI's don't support Enhanced AGI yet\n");
+		return AGI_RESULT_FAILURE;
+	}
+
+	/* format of agiurl is "hagi://host.domain[:port][/script/name]" */
+	if (!(host = ast_strdupa(agiurl + 7))) { /* Remove hagi:// */
+		ast_log(LOG_WARNING, "An error occurred parsing the AGI URI: %s", agiurl);
+		return AGI_RESULT_FAILURE;
+	}
+
+	/* Strip off any script name */
+	if ((c = strchr(host, '/'))) {
+		*c = '\0';
+		c++;
+		script = c;
+	}
+	if ((c = strchr(host, ':'))) {
+		ast_log(LOG_WARNING, "Specifying a port number disables SRV lookups: %s\n", agiurl);
+		return launch_netscript(agiurl+1, argv, fds, efd, opid); /* +1 to strip off leading h from hagi:// */
+	}
+
+	memset(service, 0, sizeof(service));
+	snprintf(service, sizeof(service), "%s%s", SRV_PREFIX, host);
+	srv_ret = ast_srv_lookup(&context, service);
+
+	AST_LIST_TRAVERSE_SAFE_BEGIN(&context.entries, current, list) {
+		memset(resolved_uri, 0, sizeof(resolved_uri));
+		snprintf(resolved_uri, sizeof(resolved_uri), "agi://%s:%d/%s", current->host, current->port, script);
+		result = launch_netscript(resolved_uri, argv, fds, efd, opid);
+		if (result == AGI_RESULT_FAILURE || result == AGI_RESULT_NOTFOUND) {
+			ast_log(LOG_WARNING, "AGI request failed for host %s\n", current->host);
+		} else {
+			break;
+		}
+	}
+	AST_LIST_TRAVERSE_SAFE_END;
+
+	while ((current = AST_LIST_REMOVE_HEAD(&context.entries, list)))
+		ast_free(current);
+
+	return result;
+}
+
 static enum agi_result launch_script(struct ast_channel *chan, char *script, char *argv[], int *fds, int *efd, int *opid)
 {
 	char tmp[256];
@@ -610,6 +687,8 @@ static enum agi_result launch_script(str
 
 	if (!strncasecmp(script, "agi://", 6))
 		return launch_netscript(script, argv, fds, efd, opid);
+	if (!strncasecmp(script, "hagi://", 7))
+		return launch_ha_netscript(script, argv, fds, efd, opid);
 	if (!strncasecmp(script, "agi:async", sizeof("agi:async")-1))
 		return launch_asyncagi(chan, argv, efd);