INTEGER {create-session-request(32),create-session-response(33),modify-bearer-request(34),modify-bearer-response(35),delete-session-request(36),delete-session-response(37),change-notification-request(38),change-notification-response(39),modify-bearer-command(64),modify-bearer-failure-indication(65),delete-bearer-command(66),delete-bearer-failure-indication(67),bearer-resource-command(68),bearer-resource-failure-indication(69),downlink-data-notification-failure-indication(70),trace-session-activation(71),trace-session-deactivation(72),stop-paging-indication(73),create-bearer-request(95),create-bearer-response(96),update-bearer-request(97),update-bearer-response(98),delete-bearer-request(99),delete-bearer-response(100),delete-pdn-connection-set-request(101),delete-pdn-connection-set-response(102),suspend-notification(162),suspend-acknowledge(163),resume-notification(164),resume-acknowledge(165),create-indirect-data-forwarding-tunnel-request(166),create-indirect-data-forwarding-tunnel-response(167),delete-indirect-data-forwarding-tunnel-request(168),delete-indirect-data-forwarding-tunnel-response(169),release-access-bearers-request(170),release-access-bearers-response(171),downlink-data-notification(176),downlink-data-notification-ack(177),update-pdn-connection-set-request(200),update-pdn-connection-set-response(201),start-of-gtpv1-messages(1000),version-not-supported-indication(1003),create-pdp-ctxt-request(1016),create-pdp-ctxt-response(1017),update-pdp-ctxt-request(1018),update-pdp-ctxt-response(1019),delete-pdp-ctxt-request(1020),delete-pdp-ctxt-response(1021),initiate-pdp-ctxt-activation-request(1022),initiate-pdp-ctxt-activation-response(1023),error-indication(1026),pdu-notification-request(1027),pdu-notification-response(1028),pdu-notification-reject-request(1029),pdu-notification-reject-response(1030),ms-info-change-notification-request(1128),ms-info-change-notification-response(1129)}