Cisco Technology, Inc.

Daniel C Frost

Stewart Frederick Bryant

Clarence Filsfils

Carlos M Pignataro

David Delano Ward

Nagendra Kumar Nainar

John William Evans

Simon James Trevor Spraggs

Muthurajah Sivabalan

George Swallow

Rex Emmanuel Fernando

Jim Guichard

Neil Jarvis

Don R Heidrich

An apparatus and method is disclosed for segment routing (SR). In one embodiment, the method includes a node creating a segment stack that identifies one segment calculated using a first algorithm and a second segment calculated using a second, different algorithm. The node then attaches this header to a packet and sends it to another node.

Segment routing techniques

A method, communications processing device, and computer readable medium for MPLS segment routing are disclosed. One embodiment of the method comprises generating a first link-state packet comprising a first data structure. The first data structure maps a first portcode to a link connecting the first router within the network or to an additional router reachable from the first router. The method embodiment further includes receiving an incoming data packet encapsulated with a header comprising an incoming portcode stack having the first portcode as its uppermost portcode. The method embodiment further includes removing the first portcode from the incoming portcode stack to create an outgoing portcode stack for an outgoing data packet, and forwarding the outgoing data packet via a port, of the first router, identified by the first portcode.

MPLS segment routing

A method, network device, and computer readable medium are disclosed. In one embodiment of the method, a data packet is received at a node within a first segment routing enabled access network. The first access network is connected, via a first area edge node, to a first area of a subdivided segment routing enabled network, and a specified destination for the data packet is reachable via a second segment routing enabled access network connected to the subdivided network. The method embodiment further includes receiving from a centralized controller a remote segment identifier stack, where the remote segment identifier stack encodes a path extending from the first area edge node to the second access network. The embodiment of the method continues with encapsulating the data packet with a full segment identifier stack comprising the remote segment identifier stack, and forwarding the encapsulated data packet toward the first area edge node.

Seamless segment routing

MPLS segment routing is disclosed. In one embodiment, a first core router generates a first data structure that maps first portcodes to respective identities of first neighbor routers or respective first links, wherein the first portcodes identify respective first ports of the first core router, and wherein the first ports are coupled to the first neighbor routers, respectively, via the first links, respectively. The first core router generates and transmits a first link-state packet, wherein the first link-state packet comprises an identity of the first core router and the first data structure.

MPLS segment-routing

A method, apparatus, and computer readable medium are disclosed. In one embodiment of the method, a packet and a segment ID stack is received at a first segment routing enabled node. The segment ID stack includes a plurality of segment IDs, one or which is a first area-segment ID that identifies a first area of a subdivided segment routing network. An egress interface of the first segment routing enabled node is selected based on the first area-segment ID. Thereafter, the packet is forwarded via the selected egress interface.

In one embodiment, operations analysis of packet groups identified based on timestamps is performed. One embodiment includes sending a plurality of sent timeframe groups of a plurality of time-stamped packets from a first packet network node towards a second packet network node in a network and recording first information associated with each of the plurality of said sent timeframe groups of the plurality of time-stamped packets. The second network node receives a plurality of received timeframe groups of a received plurality of time-stamped packets of said sent plurality of time-stamped packets and recording second information associated with each of the plurality of said received timeframe groups of the received plurality of time-stamped packets. Operations analysis based on one or more operations characteristics of said first information and said second information to produce analysis results.

Operations analysis of packet groups identified based on timestamps

A method and device are disclosed for opportunistic compression of routing segment identifiers. In one embodiment, the method includes participating in routing of a first data packet through a first node in a network, and subsequently entering into an arrangement with an adjacent node in the network. The first data packet includes a first plurality of routing segment identifiers, and additional data packets to be routed through the first node also include the first plurality of routing segment identifiers. The arrangement entered into includes representation of the first plurality of routing segment identifiers by a single compression identifier. The method further includes participating in routing of at least one of the additional data packets using the compression identifier instead of the first plurality of routing segment identifiers. In an embodiment, the device includes one or more network interfaces and a processor configured to perform the steps of the method.

Opportunistic compression of routing segment identifier stacks

In an embodiment, a method comprises: receiving a data communications packet comprising one or more labels in a label stack; determining whether a table identifier is present in the label stack. In response to determining that the table identifier is present in the label stack: based, at least in part, on the table identifier, a label table is determined; a next hop for the data communications packet is determined by performing a next-hop lookup in the label table using at least one of the one or more labels; and the data communications packet is forwarded to the next hop. In an embodiment, the method is performed by one or more computing devices.

Universal labels in internetworking

One or more functions to be performed on a packet at one or more network nodes along a network path are determined at a network device. A packet is generated which includes a packet header. Included in the packet header are an instruction pointer and an instruction portion. A first instruction for the one or more functions to be performed at the one or more network nodes is written to the instruction portion. Additionally, a value pointing to the first instruction is written to the instruction pointer. The packet is transmitted along the network path from the network device.

Framework for dynamically programmed network packet processing

In one embodiment, a packet and a segment ID stack is received at a node. The segment ID stack includes a plurality of segment IDs, one or which is a first area-segment ID that identifies a first area of a subdivided network. One of a plurality of forwarding tables at the node is selected based on the first area-segment ID. Thereafter, the packet is forwarded based on information contained in the selected forwarding table.

A method and system are disclosed for use of segment routing in monitoring of a network path. In one embodiment, the method includes selecting a plurality of segment identifiers and assembling the segment identifiers into a segment identifier stack, where the segment identifier stack encodes a test path within the network for attempted routing of a test message. The method may further include inserting the segment identifier stack into a header associated with the test message, and forwarding the test message according to an entry in a forwarding table corresponding to the segment identifier at the top of the segment identifier stack. Interior gateway protocol advertisements may be used to communicate segment identifiers for creating or updating of the data structure or the forwarding table. In an embodiment, the system includes one or more network interfaces and a processor configured to perform the steps of the method.

Method and system for path monitoring using segment routing

In one embodiment, an apparatus in a network determines particular metadata to communicate infrastructure information associated with a particular packet to another apparatus in the network. The apparatus sends into the network the particular packet including a metadata channel, comprising said particular metadata, external to the payload of the particular packet. Examples of infrastructure metadata carried in a packet include, but are not limited to, information defining service chaining for processing of the packet, contextual information for processing of the packet, specific handling instructions of the packet, and operations, maintenance, administration (OAM) instrumentation of the packet.

Packet metadata channels carrying infrastructure metadata in networks

In one embodiment, probe-packet discovery of entropy values causing specific paths to be taken through a network is performed. One embodiment sends, from a first network node to a second network node in a network, a plurality of Equal Cost Multipath (ECMP) path-taken probe packets, each with a different entropy label, to determine a particular entropy label for each particular ECMP path of a plurality of different ECMP paths between the first network node and the second network node that will cause a packet including the particular entropy label to traverse said particular ECMP path. The ECMP paths taken by the plurality of ECMP path-taken probe packets is analyzed to determine one or more entropy labels for each different ECMP path of the plurality of different ECMP paths that will cause a packet including one of said one or more entropy labels to traverse said different ECMP path.

Growing community of inventors

Middlesex, United Kingdom

Daniel C Frost