I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US007296087B 1
`
`c12) United States Patent
`Ashwood Smith
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 7,296,087 Bl
`Nov. 13, 2007
`
`(54) DYNAMIC ALLOCATION OF SHARED
`NETWORK RESOURCES BETWEEN
`CONNECTION-ORIENTED AND
`CONNECTIONLESS TRAFFIC
`
`(75)
`
`Inventor: Peter J. Ashwood Smith, Hull (CA)
`
`(73) Assignee: Nortel Networks Limited, St. Laurent
`(CA)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.: 09/527,584
`
`(22) Filed:
`
`Mar. 17, 2000
`
`(51)
`
`Int. Cl.
`G06F 151173
`(2006.01)
`(52) U.S. Cl. ...................... 709/238; 709/226; 709/229;
`709/235; 709/242
`(58) Field of Classification Search ........ 370/229-240;
`709/241
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`6,363,053 Bl * 3/2002 Schuster et al.
`
`............ 370/230
`
`3/2002 Hsu ........................... 701/202
`6,363,319 Bl*
`6,473,404 Bl* 10/2002 Kaplan et al.
`.............. 370/238
`
`OTHER PUBLICATIONS
`
`RFC2702: Requirements for Traffic Engineering Over MPLS (D.
`J. Malcolm;
`J. Agogbua; M. O'Dell; and
`J.
`Awduche;
`McManus-Sep. 1999.
`* cited by examiner
`Primary Examiner-Syed A. Zia
`(74) Attorney, Agent, or Firm-Matthew M. Roy; Ogilvy
`Renault LLP
`
`(57)
`
`ABSTRACT
`
`Resources of a shared physical network element of a com(cid:173)
`munications network are dynamically allocated between
`connection-oriented traffic and connectionless traffic. For
`each shared physical network element of the network, a
`resource requirement of the connection-oriented traffic is
`determined; and a respective traffic metric to be used for
`routing connectionless traffic is dynamically adjusted based
`on the determined resource requirement of the connection(cid:173)
`oriented traffic. As a result, resources of the shared physical
`network element can be efficiently utilized, and congestion
`of connectionless traffic being routed through the shared
`physical network element is avoided.
`
`30 Claims, 2 Drawing Sheets
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 1 of 8
`
`

`

`U.S. Patent
`
`Nov. 13, 2007
`
`Sheet 1 of 2
`
`US 7,296,087 Bl
`
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`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 2 of 8
`
`

`

`U.S. Patent
`
`Nov. 13, 2007
`
`Sheet 2 of 2
`
`US 7,296,087 Bl
`
`START
`
`RECEIVE MPLS
`RESERVATION
`REQUEST
`
`I tJO
`
`A
`
`PROCESS
`REQUEST
`
`I rJ -Z.
`
`TOTAL
`RESOURCES
`ALLOCATED
`TO MPLS
`
`QUERY IGP
`TABLE
`
`101
`
`I 0 b
`
`No
`
`WAIT
`
`/OB
`
`OBTAIN IGP
`METRIC
`
`No----<
`
`110
`
`Yes
`
`I Au:RM I
`
`Yes
`
`UPDATE LOCAL
`PATH DATABASE
`
`//?....
`
`PROPAGATE
`LINK STATE
`PACKET
`
`1111
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 3 of 8
`
`

`

`US 7,296,087 Bl
`
`1
`DYNAMIC ALLOCATION OF SHARED
`NETWORK RESOURCES BETWEEN
`CONNECTION-ORIENTED AND
`CONNECTIONLESS TRAFFIC
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This is the first application filed for the present invention.
`
`MICROFICHE APPENDIX
`
`Not Applicable.
`
`TECHNICAL FIELD
`
`2
`the resources reserved for connection-oriented traffic.
`Accordingly, during periods of heavy demand for connec(cid:173)
`tion-oriented traffic, the provisioned IGP metric for a link
`may provide an inflated indication of the amount of band(cid:173)
`width actually available for connectionless traffic. This can
`easily result in undesirable congestion on the link. Con(cid:173)
`versely, during periods of low demand for connection(cid:173)
`oriented traffic, the provisioned IGP metric for a link may
`provide a deflated indication of the amount of band-width
`10 actually available for connectionless traffic. This can result
`in undesirable under-utilization of the link.
`A technique which allows connection-oriented and con(cid:173)
`nectionless traffic to efficiently share network resources is
`therefore highly desirable.
`
`15
`
`SUMMARY OF THE INVENTION
`
`The present invention relates to resource management in
`communications networks, and in particular to dynamic
`allocation of shared network resources between connection(cid:173)
`oriented and connectionless traffic in a communications 20
`network.
`
`BACKGROUND OF THE INVENTION
`
`In the modern network space, packetized data traffic of
`various different protocols (e.g. internet protocol, frame
`relay, asynchronous transfer mode, etc.) is transported over
`a common network infrastructure. Each protocol provides its
`own packet (or frame) size and format standards. Addition(cid:173)
`ally, some protocols (e.g. IP) are specifically designed to
`allow packets having widely varying lengths. New routing
`protocols, for example the multi-protocol label switching
`(MPLS) protocol have been proposed to facilitate multi(cid:173)
`protocol traffic across a common network infrastructure.
`Under the MPLS protocol, label switched paths (LSPs) 35
`are propagated across the network hop-by-hop along a path
`that is set up at the beginning of a communications session.
`In a general, the label assigned to the LSP can be different
`for each hop, with the label conversion being performed by
`the node serving the respective hop. Resources of each hop 40
`(i.e. the node serving the hop) of the path are reserved during
`set-up of the path, and normally will not be available for
`carrying other traffic until the path is released.
`The mapping of an end-to-end path at the beginning of a
`communications session characterizes the MPLS protocol as 45
`"connection oriented". Other protocols, (such as IP) which
`do not transport data over predefined end-to-end paths are
`referred to as "connectionless". Typically, connectionless
`traffic is routed across a network using a shortest-path or
`least-cost-path routing protocol, such as, for example, the 50
`Interior Gateway Protocol (IGP). In general, a metric (e.g. a
`link distance vector, or a link cost factor) is assigned to each
`link and used within each router for mapping packet desti(cid:173)
`nation addresses to downstream links. The metric is nor(cid:173)
`mally provisioned for traffic engineering, and reflects not 55
`only geographic distances, but also provisioned bandwidth
`of each link. A higher metric on a particular link makes that
`link less attractive for carrying connectionless traffic, so that
`the IGP will normally operate to route connectionless traffic
`away from that link. Both connection-oriented and connec- 60
`tionless traffic may be carried over shared network infra(cid:173)
`structure. This situation is normally accommodated by
`adjusting the provisioned IGP metric to reflect an average
`anticipated amount of bandwidth allocated to the connec(cid:173)
`tion-oriented traffic. However, this raises a difficulty in that 65
`the amount of resources (e.g. bandwidth) actually available
`for use by connectionless traffic, on any link, will vary with
`
`An object of the present invention is to provide a tech(cid:173)
`nique for efficiently allocating resources of a shared network
`element between connection oriented and connectionless
`traffic.
`A further object of the present invention is to provide a
`method of allocating resources between connection oriented
`and connectionless traffic, by adjusting an IGP metric in
`25 accordance with MPLS resource reservations.
`Accordingly, an aspect of the present invention provides
`a shared network element operative within a communica(cid:173)
`tions network capable of end-to-end transport of connection(cid:173)
`oriented traffic and connectionless traffic through the shared
`30 network element. The shared network element comprises:
`means for determining a resource requirement of the con(cid:173)
`nection-oriented traffic; and means for dynamically adjust(cid:173)
`ing a respective traffic metric to be used for routing con(cid:173)
`nectionless
`traffic based on the determined resource
`requirement of the connection-oriented traffic.
`Another aspect of the present invention provides a method
`of managing an allocation of resources between connection(cid:173)
`oriented traffic and connectionless traffic being routed
`through a shared physical network element of a communi(cid:173)
`cations network. The method comprises the steps of: deter(cid:173)
`mining a resource requirement of the connection-oriented
`traffic; and dynamically adjusting a respective traffic metric
`to be used for routing connectionless traffic based on the
`determined resource requirement of the connection-oriented
`traffic.
`In embodiments of the invention, the connection-oriented
`traffic is multi-protocol label switched (MPLS) traffic. In
`such cases, the step of determining the resource requirement
`of the connection-oriented traffic comprises the steps of:
`receiving MPLS reservation requests in respect of the shared
`physical network element; and dynamically adjusting a total
`amount of resources required to satisfy the received MPLS
`reservation requests.
`In embodiments of the invention, the connectionless
`traffic includes internet protocol (IP) packet traffic. In such
`cases, routing of the connectionless traffic may be controlled
`using an interior gateway protocol (IGP) routing system
`adapted to calculate a shortest path route of the connection(cid:173)
`less traffic through the communications network, the short-
`est path routing being based on a respective metric concern(cid:173)
`ing each physical network element forming the network.
`The step of dynamically adjusting the respective metric
`preferably comprises the steps of: increasing the respective
`metric as the determined resource requirement of the con(cid:173)
`nection-oriented traffic increases; and decreasing the respec(cid:173)
`tive metric as the determined resource requirement of the
`connection-oriented traffic decreases.
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 4 of 8
`
`

`

`US 7,296,087 Bl
`
`3
`In some embodiments of the invention, the respective
`metric may be a link distance vector associated with a
`respective link connected to a node of the communications
`network. In such cases, the step of dynamically adjusting the
`respective metric comprises the steps of: determining an
`updated value of the link distance vector; and updating a
`mapping table maintained by the node with the updated
`value of the link distance vector.
`An updated value of the link distance vector may be
`determined by querying a resource allocation table compris- 10
`ing a plurality of characteristic resource allocation values
`and a respective link distance vector value corresponding to
`each characteristic resource allocation value. Querying the
`resource allocation table may include the steps of: identify(cid:173)
`ing the characteristic resource allocation value which most 15
`closely matches the determined resource requirement of the
`connection-oriented traffic; and selecting the corresponding
`link distance vector as the updated link cost factor.
`In other embodiments of the invention, the respective
`metric may be a link cost factor associated with a respective 20
`link connected to a node of the communications network. In
`such cases, the step of dynamically adjusting the respective
`metric comprises the steps of: determining an updated value
`of the link cost factor; updating a PATH database maintained
`by the node with the updated link cost factor value; and
`propagating a link state packet containing the updated link
`cost factor value to neighboring nodes within the network.
`An updated value of the link cost factor can be determined
`by querying a resource allocation table comprising a plu(cid:173)
`rality of characteristic resource allocation values and a
`respective link cost factor value corresponding to each
`characteristic resource allocation value. Querying the
`resource allocation table may comprise the steps of: identi(cid:173)
`fying the characteristic resource allocation value which most
`closely matches the determined resource requirement of the
`connection-oriented traffic; and selecting the corresponding
`link cost factor as the updated link cost factor.
`An advantage of the present invention is that by adjusting
`the IGP metric for a link in accordance with changing
`resource requirements of connection oriented traffic, routing
`of connectionless traffic is automatically altered to make
`effective use of remaining resources while avoiding conges(cid:173)
`tion. No modification of conventional (e.g. IGP) routing
`methodologies are required to accomplish this result.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Further features and advantages of the present invention
`will become apparent from the following detailed descrip(cid:173)
`tion, taken in combination with the appended drawings, in
`which:
`FIG. 1 is a block diagram illustrating a communications
`network usable in conjunction with an embodiment of the
`present invention; and
`FIG. 2 is a flow chart illustrating exemplary steps in a
`process for managing resource allocation in accordance with
`an embodiment of the present invention.
`It will be noted that throughout the appended drawings,
`like features are identified by like reference numerals.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`The present invention provides a system for allocating
`resources between connectionless and connection-oriented
`traffic through a communications network. As shown in FIG.
`1, a communications network 2 usable in conjunction with
`
`4
`the present invention generally comprises a plurality of
`routers 4 (four are shown in FIG. 1) interconnected by links
`6. The links 6 may be fiber optic links. The routers 4 may be
`agile or non-agile optical routers, and may be configured for
`wave division multiplex (WDM) and/or dense wave division
`multiplex (DWDM) transport of packet data traffic. Com(cid:173)
`munications devices 8, for example end user personal com(cid:173)
`puters (PCs) or local area network (LAN) servers may be
`connected to the communications network 2 via one or more
`access points 10. The communications network 2 may also
`be connected to one or more federated networks 12, for
`example an ATM or an IP network, through a respective
`gateway 14.
`In the example of FIG. 1, connection-oriented traffic is
`conveyed through an end-to-end MPLS path 16 mapped
`across the communications network 2 between a source
`node and a destination node via one or more intervening
`routers 4. The path 16 is divided into hops 18, each of which
`is served a respective node (e.g. the source node or a router
`4) connected at the up-stream end of the respective hop 18.
`In the illustrated example, the source and destination nodes
`are located at respective access points lOa and lOb, and two
`intervening routers 4a and 4b are incorporated into the path
`16. A first hop 18a of the path 16 extends between the source
`25 node at access point lOa and a first router 4a. A second hop
`l8b extends between the routers 4a and 4b. Finally, a third
`hop 18c extends between the router 4b and the destination
`node at access point lOb.
`In addition, connectionless traffic is transported through
`30 the communications network between the gateway 14 and
`the destination node lOb. Routing of the connectionless
`traffic is handled, for example, in accordance with conven(cid:173)
`tional least cost path routing using the Interior Gateway
`Protocol (IGP) to map destination addresses to downstream
`35 links. In the example illustrated in FIG. 1, a least cost path
`20 calculated using provisioned IGP metrics for each link
`follows the route indicated by dashed arrows. As may be
`seen in FIG. 1, this least cost path 20 shares two hops (18b
`and 18c) with the MPLS path 16, which may lead to
`40 congestion on those hops. Thus the present invention pro(cid:173)
`vides a technique of managing the allocation of resources
`between the two traffic flows, in order to avoid congestion
`within the shared hops.
`In accordance with the present invention, congestion
`45 within shared physical elements of the network (e.g. within
`the routers 4a, 4b and links 6 of the shared hops 18b, 18c)
`is avoided by adjusting the IGP metrics concerning each of
`the shared links 6 to reflect the resources (e.g. bandwidth)
`which have been allocated to the MPLS path 16. Adjustment
`50 of the IGP metric in this manner makes each of the shared
`links 6 less attractive for either shortest-distance-path rout(cid:173)
`ing or least-cost-path routing. In cases where either the
`bandwidth allocated to the MPLS path 16, or the volume of
`connectionless traffic is large, the adjusted IGP metrics on
`55 the shared links 6 may cause the routing protocol to favour
`an alternative path 22 (indicated by dotted arrows in FIG. 1)
`which avoids sharing links 6 with the MPLS path 16.
`Adjustment of IGP metrics can be based on a resource
`allocation table 24 which may be co-resident within each
`60 router 4 or centrally located and accessible by each router 4
`through the network 2. The resource allocation table 24
`generally operates to receive a query from a node (any of
`access points 10, routers 4, or gateway 14) containing a
`value indicative of resources allocated to connection ori-
`65 ented traffic (in the present example bandwidth allocated to
`the MPLS path 16). The resource allocation table 24 returns
`a response message to the node containing an updated value
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 5 of 8
`
`

`

`US 7,296,087 Bl
`
`5
`of an IGP metric. The node can then update its local path
`database (not shown) and propagate a link state packet to
`neighbouring nodes of the network so that conventional IGP
`routing can proceed on the basis of the updated IGP metric.
`Exemplary steps in a process of adjusting the IGP metric for
`a link 6 connected to a router 4 within the network 2 are
`described below with respect to FIG. 2.
`Adjustment of IGP metrics for each link 6 is preferably
`performed by the associated node during the set up of an
`MPLS path 16 through that node. Accordingly, as shown in 10
`FIG. 2, when an MPLS reservation request is received at a
`node (step 100), the request is processed in a conventional
`manner (step 102) and resources of the node (and a down(cid:173)
`stream link) are allocated to a hop of an MPLS path 16 being
`set up across the communications network 2. Once resources 15
`have been allocated to the MPLS path 16, the node operates
`to determine a total resource allocation to connection ori(cid:173)
`ented traffic over the involved downstream link 6 (step 104).
`The node then formulates a query message containing the
`total amount of allocated resources (step 106) and forwards 20
`the query message to the resource allocation table 24. Upon
`receipt of the query message from the node, the resource
`allocation table 24 determines an adjusted IGP metric value
`(step 108) and sends a response message to the node
`containing the adjusted IGP metric value. If the response 25
`message is received by the node prior to expiry of a
`predetermined time out period (step 110), the node operates
`to update its local path database with the adjusted IGP metric
`value for the downstream link involved in the newly set up
`MPLS path 16 (step 112). This change in the local path 30
`database of the node automatically triggers the generation of
`a link state packet which is propagated to neighbouring
`nodes within the network for handling in a conventional
`manner (step 114).
`While not shown in the drawings, it will be appreciated 35
`that an analogous process may be executed within a node to
`adjust the IGP metric as resources allocated to connection
`oriented traffic are released (e.g. as an MPLS path is taken
`down). Thus when an MPLS path release message is
`received at a node, the message is processed in a conven- 40
`tional manner, and resources of the node (and a downstream
`link) allocated to a hop of an MPLS path across the
`communications network are released. Once resources have
`been released, the node operates to determine a total amount
`of resources allocated to connection oriented traffic over the 45
`involved downstream link. The node then formulates a query
`message containing the total resource allocation, and for(cid:173)
`wards the query message to the resource allocation table.
`Upon receipt of the query message from the node, the
`resource allocation table determines an adjusted IGP metric 50
`value and sends a response message to the node containing
`the adjusted IGP metric value. If the response message is
`received by the node prior to a predetermined time out
`period, the node operates to update its local path database
`with the adjusted IGP metric value for the downstream link 55
`involved in the recently released MPLS path. This change in
`the local path database of the node automatically triggers the
`generation of a link state packet which is propagated to
`neighbouring nodes within the network for handling in a
`normal manner
`Various techniques may be used within the resource
`allocation table 24 to determine adjusted values for the IGP
`metric. For example, the resource allocation table 24 may
`contain a list of characteristic resource allocation values, and
`corresponding IGP metric values. In this case, upon receipt 65
`of a query message from a node, the resource allocation is
`extracted from the query message and compared to the
`
`60
`
`6
`characteristic values in the resource allocation table 24. The
`IGP metric value corresponding to the characteristic value
`which most closely matches
`the resource allocation
`extracted from the query message is then selected as the
`adjusted IGP metric, and sent back to the node in the
`response message. In an alternative embodiment, and in
`order to accommodate differing bandwidth capacities of
`links within the network, at least the characteristic resource
`allocation values within the resource allocation table 24 may
`be proportional, and so may represent a fraction of the total
`available bandwidth that has been allocated to connection(cid:173)
`oriented traffic.
`The embodiment(s) of the invention described above
`is(are) intended to be exemplary only. The scope of the
`invention is therefore intended to be limited solely by the
`scope of the appended claims.
`
`I claim:
`1. A method of managing a logical allocation of resources
`between connection-oriented traffic and connectionless traf(cid:173)
`fic being routed through a shared physical network element
`of a communications network, the method comprising the
`steps of:
`a) determining a resource requirement of the connection(cid:173)
`oriented traffic;
`b) dynamically adjusting a respective traffic metric to be
`used for routing connectionless traffic based on the
`determined resource requirement of the connection(cid:173)
`oriented traffic; and
`c) routing the connectionless traffic based on the adjusted
`traffic metric,
`thereby providing the logical allocation of resources for
`connectionless traffic based on the resource requirement of
`connection-oriented traffic.
`2. A method as claimed in claim 1, wherein the connec(cid:173)
`tion-oriented traffic comprises multi-protocol label switched
`(MPLS) traffic.
`3. A method as claimed in claim 2, wherein the step of
`determining the resource requirement of the connection(cid:173)
`oriented traffic comprises the steps of:
`a) receiving MPLS reservation requests in respect of the
`shared physical network element; and
`b) dynamically adjusting a total amount of resources
`required to satisfy the received MPLS reservation
`requests.
`4. A method as claimed in claim 1, wherein the connec(cid:173)
`tionless traffic comprises internet protocol (IP) packet traffic.
`5. A method as claimed in claim 4, wherein routing of the
`connectionless traffic is controlled using an interior gateway
`protocol (IP) routing system adapted to calculate a shortest
`path route of the connectionless traffic through the commu(cid:173)
`nications network, the shortest path routing being based on
`a respective metric of each physical network element form(cid:173)
`ing the network.
`6. A method as claimed in claim 5, wherein the step of
`dynamically adjusting the respective metric comprises the
`steps of:
`a) increasing the respective metric as the determined
`resource requirement of the connection-oriented traffic
`increases; and
`b) decreasing the respective metric as the determined
`resource requirement of the connection-oriented traffic
`decreases.
`7. A method as claimed in claim 5, wherein the respective
`metric is a link distance vector associated with a respective
`link connected to a node of the communications network.
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 6 of 8
`
`

`

`US 7,296,087 Bl
`
`7
`8. A method as claimed in claim 7, wherein the step of
`dynamically adjusting the respective metric comprises the
`steps of:
`a) determining an updated value of the link distance
`vector; and
`b) updating a mapping table maintained by the node with
`the updated value of the link distance vector.
`9. A method as claimed in claim 8, wherein the step of
`determining an updated value of the link distance vector
`comprises a step of querying a resource allocation table 10
`comprising a plurality of characteristic resource allocation
`values and a respective link distance vector value corre(cid:173)
`sponding to each characteristic resource allocation value.
`10. A method as claimed in claim 9, wherein the step of
`querying the resource allocation table comprises the steps 15
`of:
`a) identifying the characteristic resource allocation value
`which most closely matches the determined resource
`requirement of the connection-oriented traffic; and
`b) selecting the corresponding link distance vector as the
`updated link cost factor.
`11. A method as claimed in claim 5, wherein the respec(cid:173)
`tive metric is a link cost factor associated with a respective
`link connected to a node of the communications network.
`12. A method as claimed in claim 10, wherein the step of 25
`dynamically adjusting the respective metric comprises the
`steps of:
`a) determining an updated value of the link cost factor;
`b) updating a PATH table maintained by the node with the
`updated link cost factor value; and
`c) propagating a link state packet containing the updated
`link cost factor value to neighboring nodes within the
`network.
`13. A method as claimed in claim 12, wherein the step of
`determining an updated value of the link cost factor com- 35
`prises a step of querying a resource allocation table com(cid:173)
`prising a plurality of characteristic resource allocation val(cid:173)
`ues and a respective link cost factor value corresponding to
`each characteristic resource allocation value.
`14. A method as claimed in claim 13, wherein the step of 40
`querying the resource allocation table comprises the steps
`of:
`a) identifying the characteristic resource allocation value
`which most closely matches the determined resource
`requirement of the connection-oriented traffic; and
`b) selecting the corresponding link cost factor as the
`updated link cost factor.
`15. A shared network element operative within a commu(cid:173)
`nications network capable of end-to-end transport of con(cid:173)
`nection-oriented traffic and connectionless traffic through 50
`the shared network element, the shared network element
`comprising:
`a) means for determining a resource requirement of the
`connection-oriented traffic; and
`b) means for dynamically adjusting a respective traffic
`metric to be used for routing connectionless traffic
`based on the determined resource requirement of the
`connection-oriented traffic; and
`c) means for routing the connectionless traffic through the
`shared network element based on the adjusted traffic 60
`metric,
`thereby providing a logical allocation of resources for con(cid:173)
`nectionless traffic based on the resource requirement of
`connection-oriented traffic.
`16. A shared network element as claimed in claim 15, 65
`wherein the connection-oriented traffic comprises multi(cid:173)
`protocol label switched (MPLS) traffic.
`
`8
`17. A shared network element as claimed in claim 16,
`wherein the means for determining the resource requirement
`of the connection-oriented traffic comprises:
`a) means for receiving MPLS reservation requests in
`respect of the shared physical network element; and
`b) means for dynamically adjusting a total amount of
`resources required to satisfy the received MPLS reser(cid:173)
`vation requests
`18. A shared network element as claimed in claim 15,
`wherein the connectionless traffic comprises internet proto(cid:173)
`col (IP) packet traffic.
`19. A shared network element as claimed in claim 18,
`wherein routing of the connectionless traffic is controlled
`using an interior gateway protocol (IGP) routing system
`adapted to calculate a shortest path route of the connection(cid:173)
`less traffic through the communications network, the short-
`est path routing being based on a respective metric of each
`physical network element forming the network.
`20. A shared network element as claimed in claim 19,
`20 wherein the means for dynamically adjusting the respective
`metric comprises means adapted to:
`a) increase the respective metric as the determined
`resource requirement of the connection-oriented traffic
`increases; and
`b) decrease the respective metric as the determined
`resource requirement of the connection-oriented traffic
`decreases.
`21. A shared network element as claimed in claim 19,
`wherein the respective metric is a link distance vector
`30 associated with a respective link connected to a node of the
`communications network.
`22. A shared network element as claimed in claim 21,
`wherein the means for dynamically adjusting the respective
`metric comprises:
`a) means for determining an updated value of the link
`distance vector; and
`b) means for updating a mapping table maintained by the
`shared network element with the updated value of the
`link distance vector.
`23. A shared network element as claimed in claim 22,
`wherein the means for determining an updated value of the
`link distance vector comprises a resource allocation table
`comprising a plurality of characteristic resource allocation
`values and a respective link distance vector value corre-
`45 sponding to each characteristic resource allocation value.
`24. A shared network element as claimed in claim 23,
`further comprising:
`a) means for identifying the characteristic resource allo(cid:173)
`cation value which most closely matches the deter(cid:173)
`mined resource requirement of the connection-oriented
`traffic; and
`b) means for selecting the corresponding link distance
`vector as the updated link cost factor.
`25. A shared network element as claimed in claim 19,
`55 wherein the respective metric is a link cost factor associated
`with a respective link connected to a node of the commu(cid:173)
`nications network.
`26. A shared network element as claimed in claim 25,
`wherein the means for dynamically adjusting the respective
`metric comprises:
`a) means for determining an updated value of the link cost
`factor;
`b) means for updating a PATH table maintained by the
`node with the updated link cost factor value; and
`c) means for propagating a link state packet containing the
`updated link cost factor value to neighboring nodes
`within the network.
`
`Cisco Systems, Inc.
`Exhibit 1015
`Page 7 of 8
`
`

`

`US 7,296,087 Bl
`
`9
`27. A shared network element as claimed in claim 26,
`wherein the means for determining an updated value of the
`link cost factor comprises a resource allocation table com(cid:173)
`prising a plurality of characteristic resource allocation val(cid:173)
`ues and a respective link cost factor value corresponding to
`each characteristic resource allocation value.
`28. A shared network element as claimed in claim 27,
`further comprising:
`a) means for identifying the characteristic resource allo(cid:173)
`cation value which most closely matches the deter- 10
`mined resource requirement of the connection-oriented
`traffic; and
`b) means for selecting the corresponding link cost factor
`as the updated link cost factor.
`29. A method of managing a logical allocation of 15
`resources between connection-oriented traffic and connec(cid:173)
`tionless traffic being routed through a shared physical net(cid:173)
`work element of a communications network, the method
`comprising the steps of:
`a) in response to a change in resources allocated to a 20
`multi-protocol label switched (MPLS) path through the
`shared physical network element, determining an
`updated total amount ofresources of the shared physi-
`cal network element allocated to connection-oriented
`traffic;
`
`10
`b) dynamically adjusting a respective updated traffic
`metric of the share