Cisco Technology, Inc.

Rahul G Patel

Pritam Shah

Dana Lynn Blair

Philip Clifford Jacobs

Sanjay Sreenath

Sravan Vadlakonda

Preety Mordani

Geir Sandbakken

Greg Harald Hakonsen

Kerry Lynn

Jan Wegger

Yoshiyuki Tsuda

Suraj Pasuparthy

In one embodiment, a method includes monitoring traffic at a network device at a receiving network site to determine if a performance threshold is violated, transmitting an alert to a sending network site if the performance threshold is violated at a path at the network device, and transmitting traffic information for the path from the network device to the sending network site. The receiving network site comprises a plurality of paths for receiving traffic from the sending network site and traffic information is transmitted to the sending network site for each of the paths if the performance threshold is violated. An apparatus and logic are also disclosed herein.

Performance monitoring in a multi-site environment

According to one aspect, a method includes monitoring traffic between a first network element and a second network element, and determining when no packets have been sent from the first network element towards the second network element within a predetermined amount of time. When it is determined that no packets have been sent from the first network element towards the second network element within the predetermined amount of time, the method includes sending at least one smart probe packet from the first network element to the second network element.

Efficiently utilizing probe packets within a network

In one embodiment, a link utilization threshold is assigned to a first link. Link utilization of the first link and of one or more second links is monitored. The first link is considered to be out-of-policy (OOP) in the event that the link utilization of the first link surpasses the link utilization threshold. In response to the first link being considered OOP, action is taken. An excess utilization of the first link is determined. One or more prefixes currently routed over the first link whose collective per prefix utilization exceeds the excess utilization are determined. Provided that the collective per prefix utilization of the one or more prefixes currently routed over the first link, if added to the link utilization of the one or more second links, would not cause the one or more second links to be considered OOP, the one or more prefixes are redirected over them.

Link policy routing based on link utilization

In one embodiment, a network device (e.g., a master controller) may detect an event on a current path in a computer network from a local network domain to a destination address prefix of a remote domain. In response, the device may dynamically (e.g., intelligently) determine a trace target destination address within the destination address prefix, and may perform (or request performance of) a Traceroute of the current path and a selection of alternate paths in the network from the local network domain to the trace target, where the Traceroute is adapted to obtain per-hop measurements along the respective traced path. The measurements may then be stored, for example, to be used for optimal path selection, fault identification reporting, etc.

Event triggered traceroute for optimized routing in a computer network

In one embodiment, methods are described to measure bandwidth limits through multiple test sites. A testing quantity of network packets is generated, the network packets are sent through a service provider network to a plurality of receivers at a testing transmission rate that exceeds an upstream transmission rate limit of the service provider network, a report indicating a received number of packets is received from each of the plurality of receivers, and an upstream transmission rate limit of the service provider network is determined based on the testing transmission and the reports. By using multiple test sites, potential bottlenecks at any one test site are reduced. A similar method can be used to calculate a downstream transmission rate limit. Once measured, the bandwidth limits may be used to adjust quality of service on an edge router or compared against a known service level agreement of the service provider network.

Multiple test site bandwidth limit measurement

A STUN message is received at a router device in a network from a client device in the network along a network path. The STUN message is evaluated for information that indicates to the router device to modify media that is subsequently sent along the network path. If the evaluating indicates that the router device is to modify the media, the media is modified in accordance with information in the STUN message that indicates attributes of the network.

Resilient video encoding control via explicit network indication

In one embodiment, a method includes obtaining a first packet included in a flow to be forwarded to a border router, and replicating the first packet to create a duplicate. The first packet is forwarded onto a first set of links, and the duplicate is forwarded onto a second set of links, to the border router. First information relating to the first packet and the first set of links, and second information relating to the duplicate and the second set of links, is obtained. The first information and the second information are used to determine whether to forward the flow on the first set of links. The first set of links is used to forward the flow if it is determined that the first set of links is to be used to forward the flow, otherwise the second set of links is used to forward the flow.

Identifying the best service provider link for performance routing

In one embodiment, two or more links, coupled to a first service provider (SP) that charges a price for utilization of services according to a first pricing structure, are combined to form a single virtual combined link. Each of the two or more links of the virtual combined link and one or more other links, coupled to a second SP that charges a price for utilization of services according to a second pricing structure, are monitored to obtain link data. The link data for the two of more links of the virtual combined link is merged to form link data for the virtual combined link. Data distribution among the virtual combined link and the one or more other links is optimized to distribute data among the virtual combined link and the one or more other links in a manner that minimizes cost.

Route optimization of services provided by one or more service providers for combined links

In one embodiment, performance parameters may be determined for each of a plurality of network address prefixes in a computer network. Based on the respective performance parameters, the prefixes may be resized through at least one of consolidation of adjacent prefixes and splitting of prefixes, and traffic may then be routed in the computer network based on the resized prefixes.

Dynamically right-sizing prefixes for network and application performance

In one embodiment, a method includes receiving at a network device information on paths to a destination node, determining a number of common nodes or links between at least two of the paths, calculating a path diversity index based on the number of common nodes or links, and selecting a route to the destination node based on the path diversity index. An apparatus for calculating path diversity index for use in route selection is also disclosed.

Path diversity index for use in route selection

A technique dynamically applies a link utilization based policy to traffic traversing links in a computer network. According to the novel technique, a link utilization threshold is assigned to one or more links. The link utilization threshold may be, for example, a maximum amount of traffic for an individual link, or a maximum difference between links (e.g., for load balanced traffic). The link utilization of the one or more links may be monitored, such as, e.g., by an optimized edge routing (OER) process. In the event that the link utilization surpasses the threshold, the link is considered to be out-of-policy (OOP), and traffic may be redirected to other available links accordingly in order to bring the link back in policy ('IN-POLICY').

A technique performs route optimization of services provided by one or more service providers (SPs) for communication links that are combined in a computer network. According to the novel technique, performance characteristics and statistics ('link data') for two or more combined links are merged to form link data for a single 'virtual combined link.' Route optimization techniques (e.g., priority-based route optimization) may then be applied to one or more virtual combined links based on the combined link data, in addition to link data for zero or more conventional single links (physical or virtual). Illustratively, a route optimization technique may be used in accordance with the present invention to efficiently and accurately minimize costs associated with services provided by a plurality of SPs, wherein each SP charges for utilization of its service based on a tiered pricing structure. The tiered pricing structure comprises one or more tiers, wherein each tier correlates to an amount of service provided by the SP and an associated cost.

In one embodiment, probe messages may be transmitted from a local domain to a set of one or more responding probe targets located beyond a plurality of probed first-hop domains of the local domain, the probe messages transmitted via each of a plurality of probed first-hop domains. A reliability of each probed first-hop domain may then be determined based on responsiveness of probe messages transmitted via each respective probed first-hop domain, such that traffic destined beyond the probed first-hop domains may be load balanced across the probed first-hop domains based on the respective reliability, regardless of a traffic-class and a destination of the traffic.

First-hop domain reliability measurement and load balancing in a computer network

In one embodiment, a first set of one or more control policies at a control server of a network domain may be transmitted to a routing master controller of the network domain, which uses a second set of one or more traffic policies to determine optimal paths for directing traffic through the domain. The routing master controller may then generate a third set of one or more integrated policies based on the first and second sets of policies, e.g., based on the knowledge and policies of both the control server and the routing master controller.

Growing community of inventors

Nashua, NH, United States of America

Rahul G Patel