Patent Application: US-90933101-A

Abstract:
a method and network subsystem for providing on demand end to end quality of service in a dynamic manner , use a combination of resource reservation protocol , load control protocol and bandwidth brokers which communicate using a predetermined protocol . the predetermined protocol may be one of common open policy service protocol and simple network management protocol for direct communication by the bbs . the network subsystem might also include differentiated services architecture which might comprise a diffserv domain including border routers and core routers . the bbs may obtain resource availability information by communicating only with the brs to the exclusion of crs . the bbs may optionally have the capability of using an rsvp aggregation protocol and may have the ability to store and manage rsvp aggregation status . the method and network subsystem may additionally use integrated service architecture which will enable achieving interoperability between intserv and diffserv through the use of an edge router on a bandwidth broker aggregator .

Description:
described hereinafter are an exemplary method and network subsystem which use a combination of bandwidth brokers , rsvp aggregation and load control protocols , to achieve a dynamic end to end qos . the qos dynamic provisioning mechanism in a diffserv domain can use a resource reservation protocol that will be able to inter - communicate with the qos mechanisms applied in neighboring domains ( diffserv or non - diffserv ). such a protocol can be the rsvp aggregation protocol described earlier but preferably with a modification . the modification can consist , for example , in that the border routers ( br ) will not anymore store the rsvp aggregated states , but these states will be stored in the bandwidth brokers ( see requirement — 4 ). [ 0091 ] fig1 generally illustrates a preferred embodiment of the invention showing sender 1101 and receiver 1102 between which end to end qos is intended to be achieved . as shown , edge router er 1 shown at 1103 interacts with sender 1101 , and edge router er 2 shown at 1102 interacts with receiver 1102 . also shown in fig1 are intserv regions 1108 , and diftserv regions 1109 interacting with bandwidth broker aggregator bba / d , shown at 1105 , bandwidth broker bb shown at 1106 , and bandwidth broker aggregator bbd / a shown at 1107 . aggregated rsvp messages 1110 flow between 1105 , 1106 , and 1106 , 1107 . as shown fig1 the network element 1105 ( bba ) is functioning as a bandwidth broker aggregator and the nework element 1104 ( bbd ) is functioning as a bandwidth broker deaggregator . furthermore , the e 2 e rsvp and rsvp aggregation messages in fig1 are exchanged between the intserv networks and the bb &# 39 ; s that are managing each diffserv domain and are used to provide the qos end to end provisioning . the intserv to diffserv interoperability ( see requirement — 6 ) can be accomplished either directly via the edge routers 1103 , 1104 ( shown in fig1 ) and the bba / bbd elements 1105 , 1107 , or , via the edge router er 1 , the first border router br 1 , and bba / bbd elements 1105 , 1107 . the management of the resources in the interior of each diffserv domain , i . e ., core routers is accomplished by each br ( see requirement — 5 ). this can be achieved by using a protocol such as load control ( shown at 1111 in fig1 ) described earlier . each bb ( 1105 , 1106 , 1107 , communicates with all the ingress br &# 39 ; s ( 1112 ) of its diffserv domain by using protocols 1118 e . g ., common open policy service ( cops ) or simple network management protocol ( snmp ). in this way the bb is able to request from all the ingress br &# 39 ; s to either reserve a certain amount of resources or refresh a reservation that has been accomplished during a previous refreshment period . each ingress br ( 1112 ) will use load control ( 1111 ) to reserve the resources requested by the bb . afterwards , each br will have to inform the bb about the amount of the resources that are actually reserved by the load control protocol . each bb must contain a reservation state that will store the total amount of resources that were reserved by the load control protocol . this reservation state is only updated if either the bba ( 1105 ) is requesting to modify it or if the resource conditions in the diffserv network , i . e ., core routers , suddenly change . as already explained earlier , the operation of the load control ( 1111 ) protocol is based on refreshment periods . if a certain amount of resources are reserved during a refreshment period , say period ( i ), then these resources will be used by the diffserv domain during period ( i + 1 ) . if these resources also have to be used during period ( i + 2 ), then these reservations have to be refreshed during period ( i + 1 ). it is proposed herein that each bb in combination with the brs will manage the refreshment procedure in its diffserv domain . during each period the bb will use its reservation state information to find out how many units of resources , per rsvp aggregated session , will have to be refreshed during the next refreshment period . resource reservation state : using among others the resource reservation state of the load control protocol the aggregated resources are reserved in all the bb &# 39 ; s that are used in the end to end communication . resource refreshment state : all the reserved resources in each diffserv domain that have to remain reserved during the next refreshment period , have to be refreshed . resource release state : all the reserved resources in each diffserv domain that have to be released during the next refreshment period , will not be refreshed . the operation of the rsvp aggregation protocol in the proposed intserv / diffserv framework during the resource reservation state depends among others on the availability of the rsvp aggregation states in the bb &# 39 ; s . there are three situations that can be identified : scenario — 1 : the bb &# 39 ; s do not contain any rsvp aggregated state . therefore , a scenario similar to the one explained in fig3 has to be used in order to create these rsvp aggregated states . scenario — 2 : the bb &# 39 ; s contain rsvp aggregated states and the new e 2 e rsvp request 1113 does not require the resizing of the rsvp aggregated states 1110 . therefore , a scenario similar to the one explained in fig4 has to be used . scenario — 3 : the bb &# 39 ; s contain rsvp aggregated states and the new e 2 e rsvp request 1113 requires the resizing of the rsvp aggregated states . therefore , a scenario similar to the one explained in fig5 has to be used . [ 0108 ] fig1 shows an exemplary intserv / diffserv operation , when rsvp aggregated states are not available in the bandwidth brokers ( bbs ). fig1 illustrates sender / edge router 1201 , receiver / edge router 1202 , ingress border routers 1212 , eggress border routers 1214 and intermediate diffserv domains 1209 . if the scenario 1 is applied to the network shown in fig1 , it is assumed that the rsvp aggregated states 1110 are not available in the bb &# 39 ; s 1105 , 1106 , 1107 at the moment that a rsvp e 2 e message 1113 arrives at the bba . the operation of the proposed intserv / diffserv for this scenario is based on the rsvp aggregation operation viewed earlier in fig3 and it can be summarized as follows : step — 1 : the sender sends an rsvp e 2 e path message to the bba . note that this can be accomplished either directly via an edge router ( shown in fig1 ) or via the edge router and the first border router that can communicate with a bba and an edge router . step — 2 : the bba 1205 receives the rsvp e 2 e path message 1213 and by using the ip tunneling encapsulation procedure or by using the new proposed in rsvp ignore option in [ balt00 ], it sends the rsvp e 2 e path message to the bbd 1207 . step — 3 : the bbd receives the rsvp e 2 e path message . the bbd depending on the number of the supported phb &# 39 ; s , sends one or more e 2 e patherr messages to the bba . in this example due to the fact that the bb &# 39 ; s have to create two rsvp aggregated states , one for an ef phb and the other for an af phb , two such messages are sent . step — 4 : the bba after receiving these two e 2 e patherr messages , creates two rsvp aggregated states , one for each phb . the bba sends two rsvp aggpath messages ( a and b ) to the neighboring bb . it is to be noted that in fig1 , this bb is contained in the “ intermediate diffserv domains ” block . note that the rsvp aggpath messages have to be sent through all the intermediate diffserv domains , i . e ., the bb &# 39 ; s , that are providing the end to end communication . step — 5 : the bbd receives these two aggpath messages and sends the rsvp e 2 e message ( after decapsulating it and adjusting its qos specifications ) to the receiver 1202 ( via an edge router ). step — 6 : the bbd by using snmp or cops will request from each ingress br in its diffserv domain to reserve the resources that were demanded by the rsvp aggpath messages . each br will have to reserve a certain predefined percentage of the total amount of the resources that must be reserved . step — 7 : each ingress br will use the load control mechanisms explained earlier to reserve the requested resources . step — 8 : each br will send a reply message to the bbd to inform the bbd about the status of this procedure . note that the reply message could be a snmp or a cops message . step — 9 : the bbd using the obtained information from all the br &# 39 ; s , creates the aggregated reservation state and it sends two aggresv messages to the neighboring bb . in fig1 this bb is contained in the “ intermediate diffserv domains ” block . note that the rsvp aggresv messages have to be sent through all the intermediate diffserv domains , i . e ., the bb &# 39 ; s , that are providing the end to end communication . step — 10 : in each intermediate diffserv domain ( i . e ., bb and brs ) and also in the initiating diffserv domain ( i . e ., bba and brs ) the functionality described in step — 6 , step — 7 , step — 8 , and step — 9 has to be repeated . the difference is that in step — 6 the snmp or cops messages will request the resources that were demanded by the received rsvp aggresv messages and not by the aggpath messages . step — 11 : the bba sends via all the intermediate bb &# 39 ; s two rsvp aggresvconfirm messages to the bbd . the messages confirm the reservation of the resources . step — 12 : the receiver ( via an edge router ) replies with a rsvp e 2 e resv message that among others contains the qos parameters ( specs ) that can be supported by the receiver . step — 13 : the bbd encapsulates the rsvp e 2 e resv message ( using ip tunneling or the rsvp ignore option ) that has been received from the receiver ( see step — 12 ) and sends it to the bba . step — 14 : the bba decapsulates it and sends it to the sender ( via an edge router ). scenario 2 ( with aggregated states but without a need for resizing ) [ 0125 ] fig1 illustrates an exemplary proposed intserv / diffserv operation when rsvp aggregated states are available in the bbs , and no resizing is needed . shown in fig1 are sender / edge router 1301 , receiver / edge router 1302 , intermediate diffserv domains 1309 , ingress brs 1312 , aggress brs 1314 , bb aggregator 1305 and bb deaggregator 1307 . in this scenario as shown in fig1 , it is considered that the rsvp aggregated states are available in the bb &# 39 ; s at the moment that a rsvp e 2 e message arrives at the bba . furthermore , it is noted that the new e 2 e rsvp request does not require the resizing of the rsvp aggregated states . the operation of the proposed intserv / diffserv for this scenario is based on the rsvp aggregation operation illustrated in fig4 and it can be summarized as follows : step — 1 : the sender sends an rsvp e 2 e path message to the bba . note that this can be accomplished either directly via an edge router ( shown in fig1 ) or via the edge router and the first border router that can communicate with a bba and an edge router . step — 2 : the bba receives the rsvp e 2 e path message and by using the ip tunneling encapsulation procedure , it sends the rsvp e 2 e path message to the bbd . step — 3 : the bbd decapsulates the rsvp e 2 e path message and it sends it to the receiver ( via an edge router ). step — 4 : the receiver replies ( via an edge router ) with a rsvp e 2 e resv message that among others contains the qos parameters that can be supported by the receiver . step — 5 : the bbd encapsulates the rsvp e 2 e resv message ( using ip tunneling or the rsvp ignore option ) that has been received from the receiver and sends it to the bba . step — 6 : the bba decapsulates it and sends it to the sender ( via an edge router ). scenario 3 ( with aggregated states but with a need for resizing in the scenario shown in fig1 , it is considered that the rsvp aggregated states are already available in the bb &# 39 ; s and that the e 2 e rsvp request requires the resizing of these states . the operation of the proposed intserv / diffserv framework for this scenario is based on the operation viewed in fig5 and can be summarized as follows : step — 1 : the sender 1401 sends an rsvp e 2 e path message to the bba 1405 . note that this can be accomplished either directly via an edge router ( shown in fig1 ) or via the edge router and the first border router that can communicate with a bba and an edge router . [ 0136 ] fig1 illustrates an example of a proposed intserv / diffserv operation when rsvp aggregated states are available in the bbs , and resizing is needed . shown in fig1 are sender / edge router 1501 , receiver / edge router 1402 , ingress brs 1412 , eggress brs 1414 , intermediate diffserv domains 1409 , bb aggregator 1405 and bb deaggregator 1407 . step — 2 : the bba receives the rsvp e 2 e path message and by using the ip tunneling encapsulation procedure or by using the new proposed rsvp e 2 e ignore option in [ balt00 ], it sends the rsvp e 2 e path message to the bbd 1407 . step — 3 : the bbd decapsulates the rsvp e 2 e path message and it sends it to the receiver 1402 ( via an edge router ). step — 4 : the receiver 1402 ( via an edge router ) replies with a rsvp e 2 e resv message that among others contains the qos parameters that can be supported by the receiver . step — 5 : the bbd 1407 , in this example , will find out that the rsvp aggregated states are not enough to support the requested qos parameters that are contained in the rsvp e 2 e resv message . therefore , the bbd 1407 will initiate a rsvp aggregated reservation resizing procedure . step — 6 : the bbd 1407 by using snmp or cops will request from each ingress br in its diffserv domain to reserve the resources that were demanded by the rsvp e 2 e resv message . each br will have to reserve a certain predefined percentage of the total amount of the resources that must be resized . step — 7 : each ingress br will use the load control mechanism ( described earlier ), to resize the requested resources . step — 8 : each br will send a reply message to the bbd to inform it about the status of this procedure . note that the reply message could be a snmp or a cops message . step — 9 : the bbd using the obtained information from all the br &# 39 ; s , resizes the aggregated reservation state and it sends one aggresv message to the neighboring bb . in fig1 this bb is contained in the “ intermediate diffserv domains ” block . note that the rsvp aggresv message has to be sent through all the intermediate diffserv domains , i . e ., the bb &# 39 ; s , that are providing the end to end communication . step — 10 : in each of the intermediate diffserv domains ( i . e ., bb and brs ) and in the initiating diffserv domain ( i . e ., bba and brs ) the functionality described in step — 6 , step — 7 , step 8 and step — 9 has to be repeated . step — 11 : the bba sends via all the intermediate bb &# 39 ; s one rsvp aggresvconfirm message to the bbd . this message confirms the resizing of the reserved resources . step — 12 : the bbd encapsulates the rsvp e 2 e resv message ( using ip tunneling or the rsvp ignore option ) that has been received from the receiver ( see step — 4 ) and sends it to the bba . step — 13 : the bba decapsulates it and sends it to the sender ( via an edge router ). due to the fact that the proposed intserv / diffserv framework is using the load control protocol to reserve the aggregated resources within each diffserv domain , it has also to refresh these resources during each refreshment period . it is noted that the refreshment procedure in each diffserv domain should be managed by the bb that is managing the qos in the diffserv domain in combination with its ingress br &# 39 ; s . in each refreshment period and for each rsvp aggregation state the bb in each diffserv domain will have to inform each br about the number of the resources that have to be refreshed . using the load control protocol each br will then refresh the reservation of the resources reserved . this operation is described earlier and it can be achieved by sending for each unit of resource one rp packet . this operation is generally illustrated in fig1 , which is an example of refreshment of the reserved resources , and shows sender / edge router 1501 , receiver / edge router 1502 , ingress brs 1512 , eggress brs 1514 , intermediate diffserv domains 1509 , bb aggregator 1505 and bb deaggregator 1507 . as explained earlier , the e 2 e rsvp reservation states are temporary states , i . e ., soft states , that have to be updated temporarily . this means that e 2 e path and e 2 e resv messages will have to be periodically retransmitted . if the states are not refreshed then they will be removed . these states may also be removed by using the e 2 e pathtear and e 2 e resvtear messages . the refreshment , update and release of the aggregated states is based on a certain predefined policy which the aggregator and deaggregator will decide when the rsvp aggregated states will be refreshed or updated ; this triggering time is not completely defined by the e 2 e rsvp messages . in particular , this predefined policy takes into account the sum of the underlying e 2 e reservations , and a certain level of trend analysis . within each diffserv domain the release of the resources is managed by each br and is accomplished by using the load control protocol . if the br does not receive any request for change in its reserved resources from the bb , then it will assume that it will have to release all the resources that it is managing . the br will release a previously reserved resource by not refreshing it . this invention offers a novel concept and method that can be used to combine an intserv region ( s ) with a dynamically provisioned diffserv domain , where the qos management is controlled by a new type of bandwidth brokers . this approach enhances and extends the intserv over diffserv framework , i . e ., solution — 4 described supra . the advantages of this new concept compared to the one described as solution — 4 given earlier are : the bb is able to directly communicate and manage only the border routers and not the core routers in the diffserv domain . the border routers will manage the resource availability and the admission control into the interior of the diffserv domain , i . e ., on the core routers . this can be achieved by using the load control protocol specified earlier . in this way the dynamic qos provisioning in diffserv architectures does not impose severe scalability problems on the bb and on the core routers of the diffserv domain . furthermore , due to the fact that the rsvp aggregated states are now only stored into the bb , the problem related to large full meshed networks will not anymore occur . in other words issue — 2 described earlier can be efficiently solved . the interoperation between the bb &# 39 ; s of each diffserv domain can be accomplished quite efficiently and easily . therefore , issue — 3 described above is efficiently solved . it is important to note that the combination of the rsvp aggregation and the load control concepts can be also used when rsvp is not applied end to end . in this case the aggregator can use a policy that can be based on local configurations and local qos management architectures , to set the dscp packets that are passing into the aggregated region . this means that this concept can also be applied on e . g ., pstn ( public switched telephone networks ), gprs ( general packet radio service ) or umts ( universal mobile telecommunications system ) networks that are using the diffserv concepts in their core networks . although preferred embodiments of the method and apparatus of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description , it will be understood that the invention is not limited to the embodiments disclosed , but includes numerous rearrangements , modifications , equivalents and substitutions without departing from the scope of the invention as set forth in the appended claims . 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