Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 401662)
+++ channels/chan_sip.c	(working copy)
@@ -3221,7 +3221,7 @@
 				goto cleanup;
 			}
 		} else {
-			timeout = -1;
+			timeout = 10000;
 		}
 
 		if (ast_str_strlen(tcptls_session->overflow_buf) == 0) {
@@ -3231,6 +3231,10 @@
 				goto cleanup;
 			} else if (res == 0) {
 				/* timeout */
+				if (ao2_ref(tcptls_session, 0) > 2) {
+					/* someone is using this tcptls_session, keep polling */
+					continue;
+				}
 				ast_debug(2, "SIP %s server timed out\n", tcptls_session->ssl ? "TLS": "TCP");
 				goto cleanup;
 			}