Method for Managing Multicast Traffic in a Data Netwrok and Network Equipment Using Said Method

Abstract

The invention relates to a method for managing multicast traffic in a data network, and network equipment using said method. Hosts ( 1, 2, 3, 4 a , 4 b , 4 c ) receive from a network interface of a router ( 9 ) traffic sent by sources ( 12, 13 ) in a multicast group. The hosts and the router communicate with one another by means of a multicast host-router communications protocol by means of which the hosts send to the router messages to request multicast traffic from sources in a multicast group. The router ( 9 ) receiving one of said messages obtains in said message identifying data which identify the host that has sent said message, and said router ( 9 ) stores in specific records for each network interface of the router, host and multicast group information about the sources the traffic of which has been requested by said host in said messages sent to the router ( 9 ).

1 . A method for transmitting multicast data packets from a multicast router, the method comprising: a) the multicast router receiving, via one or more downstream network interfaces, multicast data requests made by one or more hosts; b) the multicast router reading information data contained in the multicast data requests; c) the multicast router storing state data based on the information data contained in the multicast data requests for at least a first downstream network interface, a first multicast group address, and each specific host that requests multicast data of the first multicast group address from the first downstream network interface, the state data comprising: i) an INCLUDE state record, the INCLUDE state record comprising identifying data of the first downstream network interface through which the multicast router received the multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the specific host from which the multicast data request has been received, a source list comprising source IP addresses and a source-timer associated with each source IP address, and an INCLUDE filter mode designator; or ii) an EXCLUDE state record, the EXCLUDE state record comprising identifying data of the first downstream network interface through which the multicast router received the multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the specific host from which the multicast data request has been received, a source list comprising a requested list having source IP addresses with an associated source-timer having a value greater than zero and a exclude list comprising source IP addresses with an associated source-timer of value zero, and an EXCLUDE filter mode designator; d) the multicast router storing one or more of the INCLUDE state records for the first downstream network interface and the first multicast group address; and e) the multicast router transmitting, through the first downstream network interface, at least the multicast data packets which have as a destination IP address the first multicast group address and which have as a source IP address any source IP address from the union of all the source lists stored in the INCLUDE state records of the first downstream network interface and the first multicast group address and having a source-timer greater than zero. 
     
     
         2 . The method of  claim 1 , further comprising: a) the multicast router storing one or more EXCLUDE state records for the first downstream network interface and the first multicast group address; and b) the multicast router transmitting, through the first downstream network interface, multicast data packets which have as a destination IP address the first multicast group address and which have as a source IP address any source IP address except the sources from the intersection of all the exclude lists stored in the EXCLUDE state records of the first downstream network interface and the first multicast group address. 
     
     
         3 . The method of  claim 2 , wherein the multicast data requests are based on the IGMPv3 (Internet Group Management Protocol Version 3) protocol or a version or modification thereof. 
     
     
         4 . The method of  claim 2 , wherein the multicast data requests are based on the MLDv2 (Multicast Listener Discovery protocol Version 2) or a version or modification thereof. 
     
     
         5 . The method of  claim 2 , wherein the multicast router receives the multicast data requests in IP packets sent from the hosts and the multicast router uses the source IP address of the received IP packets as the identifying data of each of the hosts requesting multicast data. 
     
     
         6 . The method of  claim 2 , wherein the multicast router receives the multicast data requests in IP packets sent from the hosts that are carried by data frames and the multicast router uses the source MAC (Media Access Control) address of the data frames that carry the received IP packets as the identifying data of each of the hosts requesting multicast data. 
     
     
         7 . The method of  claim 2 , wherein the multicast router receives the multicast data requests in IP packets sent from the hosts that are carried by data frames and the multicast router uses the source MAC (Media Access Control) address of the data frames that carry the received IP packets and the source IP address of the received IP packets as the identifying data of each of the hosts requesting multicast data. 
     
     
         8 . The method of  claim 2 , further comprising: a) the multicast router analyzing information stored in the state records of one host; and b) based on the analyzed information, the multicast router limiting the amount of multicast data the multicast router transmits to the host. 
     
     
         9 . The method of  claim 2 , wherein the requested list is an empty list for at least one of the EXCLUDE state records. 
     
     
         10 . The method of  claim 2 , wherein the exclude list is an empty list for at least one of the EXCLUDE state records 
     
     
         11 . The method of  claim 2 , further comprising: a) the multicast router analyzing information stored in the INCLUDE state records and the EXCLUDE state records; and b) based on the analyzed information, the multicast router adjusting the multicast bandwidth which the multicast router has available for distributing among the various hosts. 
     
     
         12 . The method of  claim 2 , further comprising: a) the multicast router analyzing the information stored in the state records of a single host; and b) based on the analyzed information, the multicast router limiting the amount of multicast data the single host can request. 
     
     
         13 . A multicast router configured for performing the method for transmitting multicast packets according to  claim 1 . 
     
     
         14 . A multicast router configured for performing the method for transmitting multicast packets according to  claim 2 . 
     
     
         15 . A method for storing and updating state records usable to transmit multicast packets in a multicast router, the method comprising: a) the multicast router storing for a combination of a first downstream network interface, a first multicast group address and a first host: i) a first INCLUDE state record comprising identifying data of the first downstream network interface through which the multicast router has received the specific multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the first host from which the multicast data request has been received, a source list comprising source IP addresses and a source-timer associated with each source IP address, and an INCLUDE filter mode designator; or ii) a first EXCLUDE state record, comprising identifying data of the first downstream network interface through which the multicast router has received the specific multicast data request, identifying data of the first multicast group address from which the multicast data has been requested, identifying data of the first host from which the multicast data request has been received, a source list comprising a requested list having source IP addresses with an associated source-timer having a value greater than zero and a exclude list comprising source IP addresses with an associated source-timer of value zero, and an EXCLUDE filter mode designator; b) the multicast router receiving from the first host, via the first downstream network interface, a routing message using a multicast routing protocol, the routing message comprising identifying data of the first multicast group address; c) the multicast router reading information data contained in the routing message; and d) the multicast router replacing, based on the information data, the first state record for the combination of the first downstream network interface, the first multicast group address and the first host with a second state record without modifying the state records of other hosts for the same first downstream network interface and first multicast group address. 
     
     
         16 . The method of  claim 15 , wherein the routing message is based on the IGMPv3 (Internet Group Management Protocol Version 3) protocol or a version or modification thereof. 
     
     
         17 . The method of  claim 15 , wherein the routing message is based on the MLDv2 (Multicast Listener Discovery protocol Version 2) or a version or modification thereof. 
     
     
         18 . The method of  claim 15 , wherein: a) the first state record comprises an INCLUDE(A) state record where (A) comprises a first source list; b) the routing message comprises an IS_INCLUDE(B) type message, where (B) comprises a second source list; and c) the second state record comprises an INCLUDE(B) state record, where (B) comprises the second source list. 
     
     
         19 . The method of  claim 15 , wherein: a) the first state record comprises an INCLUDE(A) state record where (A) comprises a first source list; b) the routing message comprises an IS_EXCLUDE(B) type message, where (B) comprises a second source list; and c) the second state record comprises an EXCLUDE ({ }, B) state record having an empty requested list and a exclude list comprising the second source list (B). 
     
     
         20 . The method of  claim 15 , wherein: a) the first state record comprises an EXCLUDE (X,Y) state record where (X) is the requested list and (Y) is the exclude list; b) the routing message comprises an IS_INCLUDE(A) type message, where (A) comprises a third source list; and c) the second state record comprises an INCLUDE(A) state record, where (A) comprises the third source list.