METHOD, DEVICE AND PROGRAM FOR CONTROLLING MULTICAST ROUTE SWITCH-BACK

• Main Author: SHISHIDO TAKESHI
• Format: Patent
• Language: English
• Published: 06.03.2014
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

PROBLEM TO BE SOLVED: To switch back a multicast route and to minimize interruption time (within about one second) after restoration of multicast packet transfer in an upstream (adjacent) router in a downstream side end point router in a route switch-back section when the multicast route is switched back.SOLUTION: When a downstream side end point router in a route switch-back section restores unicast route information with restoration of a link fault and the like, an IIF switch-back propriety inquiry on related (S,G) is transmitted to an upstream (adjacent) router. The upstream (adjacent) router of the downstream side end point router in the route switch-back section restores a (S,G) entry on a multicast routing table corresponding to an object (S,G) of the IIF switch-back propriety inquiry, and transmits an IIF switch-back permission notice on (S,G) to the downstream router when a joining request to (S,G) is transmitted to the upstream router. The downstream side end point router in the route switch-back section switches back IIF in response to the IIF switch-back permission notice.