Configuring RSVP-ATM QoS Interworking

Transcription

1 Configuing RSVP-ATM QoS Intewoking Last Updated: Januay 15, 2013 This chapte descibes the tasks fo configuing the RSVP-ATM QoS Intewoking featue, which povides suppot fo Contolled Load Sevice using RSVP ove an ATM coe netwok. Fo complete conceptual infomation, see the "Signalling Oveview" module. Fo a complete desciption of the RSVP-ATM QoS Intewoking commands in this module, see the Cisco IOS Quality of Sevice Solutions Command Refeence. To locate documentation of othe commands that appea in this chapte, use the command efeence maste index o seach online. Use Cisco Featue Navigato to find infomation about platfom suppot and Cisco IOS and Catalyst OS softwae image suppot. To access Cisco Featue Navigato, go to An account on Cisco.com is not equied. Finding Featue Infomation, page 1 RSVP-ATM QoS Intewoking Configuation Task List, page 1 RSVP-ATM QoS Intewoking Configuation Examples, page 6 Finding Featue Infomation You softwae elease may not suppot all the featues documented in this module. Fo the latest caveats and featue infomation, see Bug Seach Tool and the elease notes fo you platfom and softwae elease. To find infomation about the featues documented in this module, and to see a list of the eleases in which each featue is suppoted, see the featue infomation table at the end of this module. Use Cisco Featue Navigato to find infomation about platfom suppot and Cisco softwae image suppot. To access Cisco Featue Navigato, go to An account on Cisco.com is not equied. RSVP-ATM QoS Intewoking Configuation Task List To configue RSVP-ATM QoS Intewoking, pefom the tasks descibed in the following sections. Each task is identified as eithe optional o equied. Enabling RSVP and Limiting Resevable Bandwidth, page 2 (Requied) Enabling Ceation of SVCs fo Reseved Flows, page 2 (Requied) Limiting the Peak Rate Applied to the PCR fo SVCs, page 5 (Optional) Ameicas Headquates: Cisco Systems, Inc., 170 West Tasman Dive, San Jose, CA USA

2 RSVP-ATM QoS Intewoking Configuation Task List Enabling RSVP and Limiting Resevable Bandwidth Configuing pe-vc DWRED, page 5 (Requied) Monitoing RSVP-ATM Configuation fo an Inteface, page 6 (Optional) Befoe you configue RSVP-ATM QoS Intewoking, you must enable and configue the following featues: Cisco Expess Fowading (CEF) switching (equied fo RSVP-ATM) Distibuted CEF (dcef) (equied fo pe-switched vitual cicuit (SVC) DWRED) NetFlow sevices Fo infomation about CEF and dcef, efe to the Cisco IOS Switching Sevices Command Refeence. The RSVP-ATM QoS Intewoking featue does not suppot Resouce Resevation Potocol (RSVP) with multicast. See the end of this module fo the section "RSVP-ATM QoS Intewoking Configuation Examples, page 6." Enabling RSVP and Limiting Resevable Bandwidth, page 2 Enabling Ceation of SVCs fo Reseved Flows, page 2 Limiting the Peak Rate Applied to the PCR fo SVCs, page 5 Configuing pe-vc DWRED, page 5 Monitoing RSVP-ATM Configuation fo an Inteface, page 6 Enabling RSVP and Limiting Resevable Bandwidth RSVP allows end systems o hosts on eithe side of a oute netwok to establish a eseved-bandwidth path between them to pedetemine and ensue QoS fo thei data tansmission. By default, RSVP is disabled so that it is backwad compatible with systems that do not implement RSVP. To enable RSVP on an inteface and estict the total amount of bandwidth that can be eseved fo RSVP and the amount that can be eseved fo a single RSVP esevation o flow, use the following command in global configuation mode: Command Route(config)# ip svp bandwidth [intefacekbps] [single-flow-kbps] Pupose Enables RSVP fo IP on an inteface. Fo RSVP ove ATM, esevations ae needed pimaily between outes acoss the ATM backbone. To limit the numbe of locations whee esevations ae made, enable RSVP selectively only at subintefaces coesponding to oute-to-oute connections acoss the backbone netwok. Peventing esevations being made between the host and the oute both limits VC usage and educes load on the oute. The default maximum bandwidth is up to 75 pecent of the bandwidth available on the inteface. By default, the amount esevable by a flow can be up to the entie esevable bandwidth. On subintefaces, the moe estictive of the available bandwidths of the physical inteface and the subinteface is applied. Enabling Ceation of SVCs fo Reseved Flows Nomally, esevations ae seviced when RSVP classifies packets and a queueing mechanism polices the packet. To enable establishment of an SVC to sevice each new RSVP esevation on the inteface, use the following command in inteface configuation mode: 2

3 Enabling Ceation of SVCs fo Reseved Flows RSVP-ATM QoS Intewoking Configuation Task List Command Route(config-if)# ip svp svc-equied Pupose Enables ceation of an SVC fo each new esevation made on the inteface o subinteface. To ensue defined QoS, SVCs ceated in esponse to RSVP esevation equests ae established having QoS pofiles consistent with the mapped RSVP flow specifications. The sustainable cell ate (SCR) of an ATM SVC is equal to the RSVP esevation ate; the maximum bust size (MBS) of an ATM SVC is equal to the RSVP bust size. RSVP attempts to compensate fo the cell tax when establishing the esevation so that the equested bandwidth is actually available fo IP data taffic. The sustained cell ate fomula is given as follows: atm = svp * (53/48) * (MPS + DLE + (MPS + DLE) % 48)/MPS The fomula tems used in the equation (and subsequent equations) ae descibed in the table below, followed by an explanation of how the fomula was deived. Table 1 SCR Fomula Tems Tem atm svp MPS DLE Definition ATM ate (SCR). RSVP ate. Minimum IP packet size, including the IP heades (300 bytes minimum). Data-link encapsulation ovehead. Fo RSVP ATM SVCs, ATM adaptation laye 5 (AAL5), Subnetwok Access Potocol (SNAP) encapsulation is used, which imposes a 5-byte encapsulation heade on each potocol data unit (PDU). % Modulus opeato. It yields the intege emainde fom an intege division opeation. Fo example, 57 % 53 esults in 4. CPS Cell payload size. The total numbe of bytes in all the payloads of all the cells equied to send a single packet with encapsulation. UCO Unused cell ovehead (0 to 47). COMP Compensation facto. CPS divided by MPS. Thee ae two easons fo conveting fom RSVP ate to the ATM cell ate, as follows: To account fo the ATM encapsulation heade ovehead and cell heade ovehead To account fo the fact that ATM cell sizes ae fixed 3

4 RSVP-ATM QoS Intewoking Configuation Task List Enabling Ceation of SVCs fo Reseved Flows Because a potion of the last cell is unused, it is possible that a cetain IP packet size equies moe ATM cell laye bytes. MPS + DLE is the length of the data packet that needs to be segmented into a numbe of fixed-length (48- byte payload) pieces that would then be put into a cell and sent. Because the CPS needs to be geate than o equal to MPS + DLE, CPS must be lage than MPS. CPS can be calculated as follows: CPS = ceil((mps + DLE)/48) * 48 whee ceil(x ) is the ceiling opeato that etuns the smallest intege geate than o equal to the eal numbe x. Upon expanding the implementation of the ceil(x ) opeato, the expession can be aithmetically tansfomed into the following equation: CPS = MPS + DLE + (MPS + DLE) % 48 whee (MPS + DLE) % 48 yields the intege emainde when MPS + DLE is divided by 48. Because (MPS + DLE) % 48 is equal to the UCO, the equation fo CPS can be ewitten as follows: CPS = MPS + DLE + UCO Because the IP bit ate was calculated by consideing only the IP data and heade (that is, packets of length MPS o lage), the IP bit ate ( svp) needs to be multiplied by COMP. Accoding to the table above, COMP = CPS/MPS. Thus: ATM cell payload bit ate = svp * COMP = svp * CPS/MPS When expanded, the ATM cell payload bit ate is as follows: ATM cell payload bit ate = svp * (MPS + DLE + UCO)/MPS Each ATM cell has a 5-byte heade and a 48-byte payload, esulting in a 53-byte cell. Because the entie cell needs to be accounted fo (not just the payload), we need to multiply the equation by a compensation facto of 53/48, which yields the desied equation: atm = svp * (53/48) * (MPS + DLE + UCO)/MPS Thus, the SCR of the SVC ceated to cay the RSVP flow is calculated by the following fomula: atm = svp * (53/48) * (MPS + DLE + (MPS + DLE) % 48)/MPS The ATM peak cell ate (PCR) is deived using the same fomula as the cell ate fomula. It is eithe based on the maximum line ate of the ATM inteface o on a configued maximum. The maximum bust size of the SVC is deived by the following fomula: atm = svp * (MPS + DLE + UCO)/(MPS * 48) 4

5 Limiting the Peak Rate Applied to the PCR fo SVCs RSVP-ATM QoS Intewoking Configuation Task List Note that the actual PCR, SCR, and MBS will be slightly lage than these fomulas indicate. See the task "Limiting the Peak Rate Applied to the PCR fo SVCs, page 5" fo infomation on setting the PCR of the ATM SVC. Each new RSVP esevation causes establishment of a new SVC. If an existing esevation is efeshed, no new signalling is needed. If the esevation is not efeshed and it times out, the SVC is ton down. If the esevation is efeshed but the RSVP flowspec has changed, the existing SVC is ton down and a new one with the coect QoS paametes is established. Limiting the Peak Rate Applied to the PCR fo SVCs To set a limit on the PCR of esevations fo all new RSVP SVCs established on the cuent inteface o any of its subintefaces, use the following command in inteface configuation mode: Command Route(config-if)# ip svp atm-peak-ate-limit limit Pupose Configues the peak ate limit fo new RSVP SVCs on an inteface o subinteface. Fo Contolled Load Sevice, the nominal peak ate is not defined and is taken as infinity. Consequently, the PCR is set to the available line ate. Howeve, you can use the ip svp atm-peak-ate-limit command to futhe limit the PCR to a specific value on a pe-inteface basis. Configuing pe-vc DWRED To configue Distibuted Weighted Random Ealy Detection (DWRED) with pe-vc DWRED enabled as a dop policy at the inteface level fo a specific DWRED goup, use the following command in inteface configuation mode: Command Route(config-if)# andom-detect [attach goup-name] Pupose Configues inteface-level pe-vc DWRED fo a specific DWRED goup. The pe SVC-DWRED dop policy ensues that packets that match esevations and confom to the appopiate token bucket have the highest pioity. Attaching DWRED goup definitions to the inteface to suppot pe-vc DWRED dop policy ensues that if packets must be dopped, then best-effot packets ae dopped fist and not those that confom to the appopiate QoS detemined by the token bucket of the RSVP. This dop policy meets the loss equiements of contolled load called fo by the Contolled Load Sevice class. To meet the loss goals of contolled load, it is necessay to ensue that if packets must be dopped, besteffot packets ae dopped fist. Given that packets matching esevations and confoming to the appopiate token bucket will have the highest pecedence, pe-svc DWRED is used as the dop policy. Note In ode to use pe-svc DWRED, dcef must be configued on the oute. Fo infomation on how to configue dcef, efe to the Cisco IOS Switching Sevices Configuation Guide and the Cisco IOS Switching Sevices Command Refeence. 5

6 RSVP-ATM QoS Intewoking Configuation Examples Monitoing RSVP-ATM Configuation fo an Inteface Monitoing RSVP-ATM Configuation fo an Inteface To display the peak ate limit fo the inteface, the IP Pecedence and ToS bit values configued fo packets that confom to and exceed the flowspec, and othe RSVP-elated infomation fo the inteface, such as whethe the inteface has been configued to establish SVCs to sevice esevation equest messages and whethe RSVP is enabled to attach itself to NetFlow, use the following commands in EXEC mode, as needed: Command Route# show ip svp atm-peak-ate-limit [inteface] Route# show ip svp inteface [intefacetype inteface-numbe] Route# show ip svp {pecedence tos} [inteface] Pupose Displays the cuent peak ate limit set fo an inteface, if any. Displays RSVP-elated inteface infomation. Displays the IP Pecedence bit values and type of sevice (ToS) bit values to be used to mak the ToS byte of the IP heades of all packets in an RSVP eseved path that confom to o exceed the RSVP flowspec fo a given inteface. RSVP-ATM QoS Intewoking Configuation Examples This section povides RSPV-ATM QoS Intenetwoking configuation examples. Fo infomation about configuing RSVP-ATM QoS Intenetwoking, see the" RSVP-ATM QoS Intewoking Configuation Task List" section in this module. The following example configues two Cisco 7500 seies outes that connect ove an ATM coe netwok though a pemanent vitual cicuit (PVC) and multiple SVCs. As depicted in the figue below, Route A is connected to the ATM coe netwok downsteam; upsteam it is connected acoss an Ethenet connection to the RSVP sende host system. Route B is connected upsteam to the ATM coe netwok and downsteam acoss an Ethenet connection to the RSVP eceive host. The example configuation shows thee PVCs, two of which ae equied by ATM. One of the PVCs is used fo RSVP-ATM QoS Intewoking. It is used fo tansmission of best-effot taffic and to contol taffic such as outing and RSVP messages. The ATM SVCs ae established in esponse to esevation equest messages in ode to sevice those equests. Figue 1 Example RSVP-ATM QoS Intewoking Configuation 6

7 Monitoing RSVP-ATM Configuation fo an Inteface RSVP-ATM QoS Intewoking Configuation Examples Route A Configuation The following potion of the example configues Route A in global configuation mode. It enables CEF, which must be tuned on befoe the RSVP-ATM QoS Intewoking featue can be enabled at the inteface configuation level. RouteA# config teminal RouteA(config)# ip outing RouteA(config)# ip cef The following segment of the configuation fo Route A configues ATM inteface 2/1/0. The ip outecache flowcommand enables NetFlow on the inteface. If you do not ente the ip svp bandwidthcommand befoe the ip svp svc-equiedcommand, a waning is issued equesting that you change the ode of the commands. The ip svp bandwidth command enables RSVP on the inteface with default values fo bandwidth allocation to RSVP. The ip svp svc-equiedcommand enables establishment of an SVC to sevice each new RSVP esevation on the inteface. The ip svp tos and ip svp pecedence commands configue confom and exceed values to be used fo setting the ToS and IP Pecedence bits of packets that eithe confom to o exceed the RSVP flowspec. (Note that once set, the ToS and IP Pecedence bit values emain fo the duation of the packet.) You should configue the ip oute-cache flow command only on the input intefaces of a oute on whose output intefaces you configued the ip svp svc-equied command. RouteA(config)# inteface ATM2/1/0 RouteA(config-if)# no shut RouteA(config-if)# ip addess RouteA(config-if)# no ip poxy RouteA(config-if)# no ip ediects RouteA(config-if)# ip oute-cache RouteA(config-if)# ip moute-cache RouteA(config-if)# ip oute-cache flow RouteA(config-if)# no ip moute-cache RouteA(config-if)# ip oute-cache cef RouteA(config-if)# atm pvc qsaal RouteA(config-if)# atm pvc ilmi RouteA(config-if)# atm esi-addess RouteA(config-if)# pvc pvc12 0/51 RouteA(config-if-atm-vc)# inap 5 RouteA(config-if-atm-vc)# boadcast RouteA(config-if-atm-vc)# exit RouteA(config-if)# ip svp bandwidth RouteA(config-if)# ip svp svc-equied RouteA(config-if)# ip svp tos confom 4 RouteA(config-if)# ip svp pecedence confom 3 exceed 2 The following potion of the configuation configues Ethenet inteface 0/1 on Route A that is used fo the connection between the sende host and Route A. RSVP is enabled on the inteface with default bandwidth allocations. RouteA(config)# inteface Ethenet0/1 RouteA(config-if)# ip addess RouteA(config-if)# no ip poxy RouteA(config-if)# no ip ediects RouteA(config-if)# no shut RouteA(config-if)# ip oute-cache RouteA(config-if)# ip moute-cache RouteA(config-if)# ip oute-cache flow RouteA(config-if)# no ip moute-cache RouteA(config-if)# ip oute-cache cef RouteA(config-if)# fai RouteA(config-if)# ip svp bandwidth 7

8 RSVP-ATM QoS Intewoking Configuation Examples Monitoing RSVP-ATM Configuation fo an Inteface The following section displays configuation fo Route A afte the peceding commands wee used to configue it: RouteA# wite teminal Cuent configuation: vesion 12.0 sevice timestamps debug uptime sevice timestamps log uptime no sevice passwod-encyption hostname RouteA boot system tftp sp-jv-mz enable passwod ip subnet-zeo ip cef inteface Ethenet0/1 ip addess no ip ediects no ip diected-boadcast no ip poxy-ap ip svp bandwidth no ip oute-cache cef no ip moute-cache fai-queue inteface ATM2/1/0 ip addess no ip ediects no ip diected-boadcast no ip poxy-ap ip svp bandwidth ip svp svc-equied ip oute-cache flow ip svp tos confom 4 ip svp pecedence confom 3 exceed 2 no ip oute-cache cef no ip oute-cache distibuted no ip moute-cache atm pvc qsaal atm pvc ilmi atm esi-addess pvc pvc12 0/51 inap 5 boadcast Route B Configuation Route B is configued similaly to Route A. In the following global configuation potion of the example, Route B is configued so that CEF is e enabled befoe the RSVP-ATM QoS Intewoking featue can be enabled. RouteB# config teminal RouteB(config)# ip outing RouteB(config)# ip cef The following segment of the configuation fo Route B configues ATM inteface 3/0/0. The ip svp bandwidthcommand enables RSVP and the ip oute-cache flowcommand enables NetFlow on the inteface. The ip svp svc-equiedcommand enables the RSVP-ATM QoS Intewoking featue, allowing fo the establishment of an SVC to sevice each new RSVP esevation on the inteface. RouteB(config)# inteface ATM3/0/0 RouteB(config-if)# atm pvc qsaal RouteB(config-if)# atm pvc ilmi RouteB(config-if)# atm esi-addess RouteB(config-if)# pvc pvc12 0/52 8

9 Monitoing RSVP-ATM Configuation fo an Inteface RSVP-ATM QoS Intewoking Configuation Examples RouteB(config-if-atm-vc)# inap 5 RouteB(config-if-atm-vc)# boadcast RouteB(config-if-atm-vc)# exit RouteB(config-if)# ip svp bandwidth RouteB(config-if)# ip oute-cache flow RouteB(config-if)# ip svp svc-equied The following potion of the configuation configues the Ethenet inteface on Route B. This inteface is used fo the connection between the eceive host and Route B. RSVP is enabled on the inteface. RouteB(config)# inteface Ethenet0/2 RouteB(config-if)# no shut RouteB(config-if)# ip addess RouteB(config-if)# no ip poxy RouteB(config-if)# no ip ediects RouteB(config-if)# ip oute-cache RouteB(config-if)# ip moute-cache RouteB(config-if)# ip oute-cache flow RouteB(config-if)# no ip moute-cache RouteB(config-if)# ip oute-cache cef RouteB(config-if)# fai RouteB(config-if)# ip svp bandwidth RouteB(config-if)# end RouteB(config)# ip outing RouteB(config)# oute eigp 17 RouteB(config-oute)# netwok RouteB(config-oute)# netwok The following section displays configuation fo Route B afte the peceding commands wee used to configue it: RouteB# wite teminal Cuent configuation: vesion 12.0 sevice timestamps debug uptime sevice timestamps log uptime no sevice passwod-encyption hostname RouteB boot system tftp sp-jv-mz enable passwod ip subnet-zeo ip cef distibuted inteface Ethenet0/2 ip addess no ip ediects no ip diected-boadcast no ip poxy-ap ip svp bandwidth ip oute-cache flow no ip moute-cache fai-queue inteface ATM3/0/0 ip addess no ip ediects no ip diected-boadcast no ip poxy-ap ip svp bandwidth ip svp svc-equied ip oute-cache flow no ip oute-cache cef no ip oute-cache distibuted no ip moute-cache atm pvc qsaal atm pvc ilmi atm esi-addess

10 Monitoing RSVP-ATM Configuation fo an Inteface pvc pvc12 0/52 inap 5 boadcast Cisco and the Cisco logo ae tademaks o egisteed tademaks of Cisco and/o its affiliates in the U.S. and othe counties. To view a list of Cisco tademaks, go to this URL: Thid-paty tademaks mentioned ae the popety of thei espective ownes. The use of the wod patne does not imply a patneship elationship between Cisco and any othe company. (1110R) Any Intenet Potocol (IP) addesses and phone numbes used in this document ae not intended to be actual addesses and phone numbes. Any examples, command display output, netwok topology diagams, and othe figues included in the document ae shown fo illustative puposes only. Any use of actual IP addesses o phone numbes in illustative content is unintentional and coincidental Cisco Systems, Inc. All ights eseved. 10