Fast restoration for virtually-concatenated data traffic

A method for restoration of virtually-concatenated data traffic in a network comprising at least first and second nodes, the method comprising the steps of:

• forming a virtually-concatenated group comprising:
• (i) a plurality of primary members each associated with a corresponding data stream, and (ii) at least one backup member;
• and
• responsive to a failure of a given one of the plurality of primary members, utilizing the backup member for restoring data traffic of the given member;
• wherein a route failure is indicated by member status information sent by one of the nodes operating as a sink node to another of the nodes operating as a source nodes;
• wherein the sink node maintains for the virtually-concatenated group a list of B buckets, with each bucket capable of being identified by a bucket identifier corresponding to a member status indicator, such that in the absence of failures the member status indicator values cycle from 0 to B-1;
• and
• wherein the bucket identifier of a first bucket in the list of B buckets specifies a member status indicator indicating the particular members for which member status information is sent from the sink node to the source node in a current multiframe.

A method for restoration of virtually-concatenated data traffic in a network comprising at least first and second nodes, the method comprising the steps of:

• forming a virtually-concatenated group comprising:
• (i) a plurality of primary members each associated with a corresponding data stream, and (ii) at least one backup member;
• and
• responsive to a failure of a given one of the plurality of primary members, utilizing the backup member for restoring data traffic of the given member;
• wherein a route failure is indicated by member status information sent by one of the nodes operating as a sink node to another of the nodes operating as a source node;
• wherein the sink node maintains for the virtually-concatenated group a list of B buckets, with each bucket capable of being identified by a bucket identifier corresponding to a member status indicator, such that in the absence of failures the member status indicator values cycle from 0 to B-1;
• and
• wherein in conjunction with at least one of failure of a member, recovery of a previously-failed member, and addition of a member to the virtually-concatenated group, a bucket identifier is determined for the corresponding member as a function of a sequence number of that member, and assigned to a first bucket in the list of B buckets, such that a normal cycle of the member status indicators is broken in order to expedite the sending of member status information for the affected member(s).

A method for restoration of virtually-concatenated data traffic in a network comprising at least first and second nodes, the method comprising the steps of:

• forming a virtually-concatenated group comprising:
• (i) a plurality of primary members each associated with a corresponding data stream, and (ii) at least one backup member;
• and
• responsive to a failure of a given one of the plurality of primary members, utilizing the backup member for restoring data traffic of the given member;
• wherein a route failure is indicated by member status information sent by one of the nodes operating as a sink node to another of the nodes operating as a source node;
• wherein the sink node maintains for the virtually-concatenated group a list of B buckets, with each bucket capable of being identified by a bucket identifier corresponding to a member status indicator, such that in the absence of failures the member status indicator values cycle from 0 to B-1:
• and
• wherein the list of buckets is configured such that no two buckets are assigned the same bucket identifier at any given point in time.

An apparatus for use in restoration of virtually-concatenated data traffic in a network comprising at least first and second nodes, the apparatus comprising:

• a processor;
• and
• a memory coupled to the processor;
• wherein the processor is operative to control execution of a restoration algorithm;
• and
• wherein the restoration algorithm forms a virtually-concatenated group comprising:
• (i) a plurality of primary members each associated with a corresponding data stream, and (ii) at least one backup member;
• and responsive to a failure of a given one of the plurality of primary members, utilizes the backup member for restoring data traffic of the given member;
• wherein the failure is indicated by member status information sent by one of the nodes operating as a sink node to another of the nodes operating as a source node;
• wherein particular ones of the primary members for which member status information is carried in a given framing unit are identified by a member status indicator transmitted in that framing unit;
• wherein the member status indicator is one of a plurality of member status indicators that change from framing unit to framing unit in accordance with a normal cycle of such member status indicators;
• and
• wherein in conjunction with the failure, the normal cycle of member status indicators is broken in order to expedite the sending of member status information for the given primary member.

An article of manufacture comprising a machine-readable medium containing one or more programs for use in restoration of virtually-concatenated data traffic in a network comprising first and second nodes, the one or more programs when executed implementing the steps of:

• forming a virtually-concatenated group comprising:
• (i) a plurality of primary members each associated with a corresponding data stream, and (ii) at least one backup member;
• and
• responsive to a failure of a given one of the plurality of primary members, utilizing the backup member for restoring data traffic of the given member;
• wherein the failure is indicated by member status information sent by one of the nodes operating as a sink node to another of the nodes operating as a source node;
• wherein particular ones of the primary members for which member status information is carried in a given framing unit are identified by a member status indicator transmitted in that framing unit;
• wherein the member status indicator is one of a plurality of member status indicators that change from framing unit to framing unit in accordance with a normal cycle of such member status indicators;
• and
• wherein in conjunction with the failure, the normal cycle of member status indicators is broken in order to expedite the sending of member status information for the given primary member.

A method for processing virtually-concatenated data traffic in a network comprising at least first and second nodes, the method comprising the steps of:

• forming a virtually-concatenated group comprising a plurality of members;
• and
• determining that a given one of the members has failed based at least in part on member status information sent by the second node to the first node;
• wherein the second node sends the member status information to the first node in accordance with a protocol in which a member status indicator is updatable in an arbitrary manner from multiframe to multiframe, the member status indicator for a given multiframe specifying a particular set of the members for which member status information is sent in the given multiframe;
• wherein the member status indicator is one of a plurality of member status indicators that change from multiframe to multiframe in accordance with a normal cycle of such member status indicators;
• and
• wherein in conjunction with the failure, the normal cycle of member status indicators is broken in order to expedite the sending of member status information for the given member.