Non-disruptive monitoring of traffic flows in a connection-orientated packet network

A method for converting a point-to-point packet flow from a first point to a second point in a packet switch into a point-to-multipoint packet flow from said first point to said second point and from said first point to a third point in said packet switch for monitoring packets arriving at the packet switch without disrupting said point-to-point packet flow, wherein said switch comprises one or more interface devices, connected to an internal switch bus, for servicing said first, second and third points, said method comprising the steps of:

• (a) configuring the device servicing said third point to retrieve from said bus packets addressed thereto which use a multicast addressing scheme for routing packets from said first point to said second point and from said first point to said third point;
• (b) configuring the device servicing said second point to additionally retrieve from said bus the multicast packets, wherein the device servicing the second point maintains an existing configuration to retrieve, from said bus, packets forming part of said point-to-point packet flow and which use a unicast addressing scheme;
• (c) only after step (b) is completed, configuring the device servicing said first point to address packets received at said first point to said second and third points using said multicast addressing scheme;
• and
• (d) monitoring the multicast packets arriving at said third point.

A method of processing a stream of data packets in a packet switch arriving at an input point thereof to facilitate monitoring of said stream, said method comprising the steps of:

• (a) attaching overhead associated with a point-to-point connection to packets received at the input point in order to route the packets to a first output point;
• (b) receiving and processing the packets having the point-to-point overhead attached thereto at the first output point;
• (c) configuring a device servicing the first output point to additionally receive and process packets having overhead attached thereto which is associated with a point-to-multipoint connection for routing packets from the input point to the first output point and from the input point to a second output point, wherein the device servicing the first output point maintains an existing configuration to receive and process packets having the point-to-point overhead attached thereto;
• (d) only after step (c) is completed attaching the point-to-multipoint overhead to packets received at the input point;
• and
• (e) receiving and processing the packets having the point-to-multipoint overhead attached thereto at the second output point;
• thereby converting a continuous point-to-point packet flow into a point-to-multipoint packet flow and enabling monitoring of data packets arriving at the second output point without disrupting the point-to-point packet flow.

A method of non-disruptive monitoring of a point-to-point (P2P) connection established in a connection oriented network across a switching node, comprising:

• (a) receiving at a point A on an ingress interface of the switching node a protocol data unit (PDU) carried in the P2P connection and routing the PDU to a point B on an egress interface of the switching node, said P2P connection extending through the point A to the point B;
• (b) receiving a request for monitoring the P2P connection in the point A and creating a test point C on a second egress interface of the switching node;
• (c) configuring the point A, point B and test point C for establishing a point-to-multipoint (P2M) connection between the points A and B and between the point A and test point C, without impairing operation of the P2P connection;
• (d) switching the PDU from the P2P connection to the P2M connection without tearing down the P2P connection;
• and
• (f) at the test point C, monitoring and testing the PDU and other PDU's arriving at the point A along the P2P connection.