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RSVP Scalability Enhancements
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Contents
RSVP Scalability EnhancementsLast Updated: July 24, 2012
This document describes the Cisco Resource Reservation Protocol (RSVP) scalability enhancements. It identifies the supported platforms, provides configuration examples, and lists related IOS command line interface (CLI) commands. This document includes the following major sections: Feature Information ForThe following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature. Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required. Feature OverviewRSVP typically performs admission control, classification, policing, and scheduling of data packets on a per-flow basis and keeps a database of information for each flow. RSVP scalability enhancements let you select a resource provider (formerly called a quality of service (QoS) provider) and disable data packet classification so that RSVP performs admission control only. This facilitates integration with service provider (differentiated services (DiffServ)) networks and enables scalability across enterprise networks. Class-based weighted fair queueing (CBWFQ) provides the classification, policing, and scheduling functions. CBWFQ puts packets into classes based on the differentiated services code point (DSCP) value in the packet's Internet Protocol (IP) header, thereby eliminating the need for per-flow state and per-flow processing. The figure below shows two enterprise networks interconnected through a service provider (SP) network. The SP network has an IP backbone configured as a DiffServ network. Each enterprise network has a voice gateway connected to an SP edge/aggregation router via a wide area network (WAN) link. The enterprise networks are connected to a private branch exchange (PBX). The voice gateways are running classic RSVP, which means RSVP is keeping a state per flow and also classifying, marking, and scheduling packets on a per flow basis. The edge/aggregation routers are running classic RSVP on the interfaces (labeled C and D) connected to the voice gateways and running RSVP for admission control only on the interfaces connected to core routers 1 and 3. The core routers in the DiffServ network are not running RSVP, but are forwarding the RSVP messages to the next hop. The core routers inside the DiffServ network implement a specific per hop behavior (PHB) for a collection of flows that have the same DSCP value. The voice gateways identify voice data packets and set the appropriate DSCP in their IP headers such that the packets are classified into the priority class in the edge/aggregation routers and in core routers 1, 2, 3 or 1, 4, 3. The interfaces or the edge/aggregation routers (labeled A and B) connected to core routers 1 and 3 are running RSVP, but are doing admission control only per flow against the RSVP bandwidth pool configured on the DiffServ interfaces of the edge/aggregation routers. CBWFQ is performing the classification, policing, and scheduling functions. Supported Platforms
PrerequisitesThe network must support the following Cisco IOS features before the RSVP scalability enhancements are enabled:
Configuration Tasks
Enabling RSVP on an InterfaceTo enable RSVP on an interface, use the following command, beginning in interface configuration mode:
Setting the Resource Provider
To set the resource provider, use the following command, beginning in interface configuration mode:
Disabling Data Packet ClassificationTo turn off (disable) data packet classification, use the following command, beginning in interface configuration mode:
Configuring Class and Policy MapsTo configure class and policy maps, use the following commands, beginning in global configuration mode: DETAILED STEPS
Attaching a Policy Map to an InterfaceTo attach a policy map to an interface, use the following command, beginning in interface configuration mode:
Verifying RSVP Scalability Enhancements ConfigurationSUMMARY STEPS
DETAILED STEPS Monitoring and Maintaining RSVP Scalability EnhancementsTo monitor and maintain RSVP scalability enhancements, use the following commands in EXEC mode:
Configuration Examples
Example Configuring CBWFQ to Accommodate Reserved TrafficThe following output shows a class map and a policy map being configured for voice: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# class-map match-all voice Router(config-cmap)# match access-group 100 Router(config-cmap)# exit Router(config)# policy-map wfq-voip Router(config-pmap)# class voice Router(config-pmap-c)# priority 24 Router(config-pmap-c)# end Router#
The following output shows an access list being configured: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# access-list 100 permit udp any any range 16384 32500 The following output shows a class being applied to the outgoing interface: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# int atm6/0 Router(config-if)# service-policy output wfq-voip The following output shows bandwidth being configured on an interface: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# int atm6/0 Router(config-if)# ip rsvp bandwidth 24
Example Configuring the Resource Provider as None with Data Classification Turned OffThe showrun command displays the current configuration in the router: Router# show run int atm6/0 class-map match-all voice match access-group 100 ! policy-map wfq-voip class voice priority 24 class class-default fair-queue ! interface ATM6/0 ip address 20.20.22.1 255.255.255.0 no ip redirects no ip proxy-arp no ip route-cache cef atm uni-version 4.0 atm pvc 1 0 5 qsaal atm pvc 2 0 16 ilmi atm esi-address 111111111181.00 no atm auto-configuration no atm ilmi-keepalive pvc blue 200/100 abr 700 600 inarp 1 broadcast encapsulation aal5snap service-policy output wfq-voip ! ip rsvp bandwidth 24 24 ip rsvp signalling dscp 48 access-list 100 permit udp any any range 16384 32500 Here is output from the showiprsvpinterfacedetail command before resource provider none is configured and data-packet classification is turned off:
Router# show ip rsvp interface detail
AT6/0:
Bandwidth:
Curr allocated: 190K bits/sec
Max. allowed (total): 112320K bits/sec
Max. allowed (per flow): 112320K bits/sec
Neighbors:
Using IP encap: 1. Using UDP encaps: 0
DSCP value used in Path/Resv msgs: 0x30
Here is output from the showqueueingcommand before resource provider none is configured and data packet classification is turned off: Router# s how queueing int atm6/0 Interface ATM6/0 VC 200/100 Queueing strategy: weighted fair Output queue: 63/512/64/3950945 (size/max total/threshold/drops) Conversations 2/5/64 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 450 kilobits/sec
The following output shows resource provider none being configured: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# int atm6/0 Router(config-if)# ip rsvp resource-provider none Router(config-if)# end Router# The following output shows data packet classification being turned off: Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)# int atm6/0 Router(config-if)# ip rsvp data-packet classification none Router(config-if)# end Router# Here is output from the showiprsvpinterfacedetail command after resource provider none has been configured and data packet classification has been turned off:
Router# show ip rsvp interface detail
AT6/0:
Bandwidth:
Curr allocated: 190K bits/sec
Max. allowed (total): 112320K bits/sec
Max. allowed (per flow): 112320K bits/sec
Neighbors:
Using IP encap: 1. Using UDP encaps: 0
DSCP value used in Path/Resv msgs: 0x30
RSVP Data Packet Classification is OFF
RSVP resource provider is: none
The following output from the showiprsvpinstalleddetail command verifies that resource provider none is configured and data packet classification is turned off:
Router# show ip rsvp installed detail
RSVP: ATM6/0 has the following installed reservations
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 14, Source port is 14
Reserved bandwidth: 50K bits/sec, Maximum burst: 1K bytes, Peak rate: 50K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 3192 packets (1557696 bytes)
Data given best-effort service: 42 packets (20496 bytes)
Reserved traffic classified for 271 seconds
Long-term average bitrate (bits/sec): 45880 reserved, 603 best-effort
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 10, Source port is 10
Reserved bandwidth: 20K bits/sec, Maximum burst: 1K bytes, Peak rate: 20K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 1348 packets (657824 bytes)
Data given best-effort service: 0 packets (0 bytes)
Reserved traffic classified for 296 seconds
Long-term average bitrate (bits/sec): 17755 reserved, 0M best-effort
The following output shows no increments in packet counts after the source sends data packets that match the reservation:
Router# show ip rsvp installed detail
RSVP: Ethernet3/3 has no installed reservations
RSVP: ATM6/0 has the following installed reservations
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 14, Source port is 14
Reserved bandwidth: 50K bits/sec, Maximum burst: 1K bytes, Peak rate: 50K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 3192 packets (1557696 bytes)
Data given best-effort service: 42 packets (20496 bytes)
Reserved traffic classified for 282 seconds
Long-term average bitrate (bits/sec): 44051 reserved, 579 best-effort
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 10, Source port is 10
Reserved bandwidth: 20K bits/sec, Maximum burst: 1K bytes, Peak rate: 20K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 1348 packets (657824 bytes)
Data given best-effort service: 0 packets (0 bytes)
Reserved traffic classified for 307 seconds
Long-term average bitrate (bits/sec): 17121 reserved, 0M best-effort
The following output shows that data packet classification is enabled again: Router# configure terminal Router(config)# int atm6/0 Router(config-if) no ip rsvp data-packet classification Router(config-if)# end The following output verifies that data packet classification is occurring:
Router# show ip rsvp installed detail
Enter configuration commands, one per line. End with CNTL/Z.
RSVP: ATM6/0 has the following installed reservations
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 14, Source port is 14
Reserved bandwidth: 50K bits/sec, Maximum burst: 1K bytes, Peak rate: 50K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 3683 packets (1797304 bytes)
Data given best-effort service: 47 packets (22936 bytes)
Reserved traffic classified for 340 seconds
Long-term average bitrate (bits/sec): 42201 reserved, 538 best-effort
RSVP Reservation. Destination is 145.20.20.212, Source is 145.10.10.211,
Protocol is UDP, Destination port is 10, Source port is 10
Reserved bandwidth: 20K bits/sec, Maximum burst: 1K bytes, Peak rate: 20K bits/sec
Min Policed Unit: 0 bytes, Max Pkt Size: 1514 bytes
Resource provider for this flow: None
Conversation supports 1 reservations
Data given reserved service: 1556 packets (759328 bytes)
Data given best-effort service: 0 packets (0 bytes)
Reserved traffic classified for 364 seconds
Long-term average bitrate (bits/sec): 16643 reserved, 0M best-effort
Here is output from the showrun command after you have performed all the previous configuration tasks:
Router# show run int atm6/0
class-map match-all voice
match access-group 100
!
policy-map wfq-voip
class voice
priority 24
class class-default
fair-queue
!
interface ATM6/0
ip address 20.20.22.1 255.255.255.0
no ip redirects
no ip proxy-arp
no ip route-cache cef
atm uni-version 4.0
atm pvc 1 0 5 qsaal
atm pvc 2 0 16 ilmi
atm esi-address 111111111181.00
no atm auto-configuration
no atm ilmi-keepalive
pvc blue 200/100
abr 700 600
inarp 1
broadcast
encapsulation aal5snap
service-policy output wfq-voip
!
ip rsvp bandwidth 24 24
ip rsvp signalling dscp 48
ip rsvp data-packet classification none
ip rsvp resource-provider none
access-list 100 permit udp any any range 16384 32500
Additional ReferencesRelated DocumentsMIBsTechnical Assistance
Glossaryadmission control --The process in which an RSVP reservation is accepted or rejected based on end-to-end available network resources. aggregate --A collection of packets with the same DSCP. bandwidth --The difference between the highest and lowest frequencies available for network signals. This term also describes the rated throughput capacity of a given network medium or protocol. CBWFQ -- Class-based weighted fair queueing. A queueing mechanism that extends the standard WFQ functionality to provide support for user-defined traffic classes. Class-based weighted fair queueing -- See CBWFQ . differentiated services --See DiffServ. differentiated services code point --See DSCP. DiffServ --An architecture based on a simple model where traffic entering a network is classified and possibly conditioned at the boundaries of the network. The class of traffic is then identified with a DS code point or bit marking in the IP header. Within the core of the network, packets are forwarded according to the per-hop behavior associated with the DS code point. DSCP --Differentiated services code point. The six most significant bits of the 1-byte IP type of service (ToS) field. The per-hop behavior represented by a particular DSCP value is configurable. DSCP values range between 0 and 63. enterprise network --A large and diverse network connecting most major points in a company or other organization. flow --A stream of data traveling between two endpoints across a network (for example, from one LAN station to another). Multiple flows can be transmitted on a single circuit. packet --A logical grouping of information that includes a header containing control information and (usually) user data. Packets most often refer to network layer units of data. PBX --Private branch exchange. A digital or analog telephone switchboard located on the subscriber premises and used to connect private and public telephone networks. PHB --Per hop behavior. A DiffServ concept that specifies how specifically marked packets are to be treated by each DiffServ router. QoS --Quality of service. A measure of performance for a transmission system that reflects its transmission quality and service availability. quality of service --See QoS. Resource Reservation Protocol --See RSVP. RSVP --Resource Reservation Protocol. A protocol for reserving network resources to provide quality of service guarantees to application flows. Voice over IP --See VoIP. VoIP --Voice over IP. The ability to carry normal telephony-style voice over an IP-based internet maintaining telephone-like functionality, reliability, and voice quality. Weighted Fair Queueing --See WFQ. WFQ --Weighted fair queueing. A queue management algorithm that provides a certain fraction of link bandwidth to each of several queues, based on relative bandwidth applied to each of the queues. Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R) Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental. © 2012 Cisco Systems, Inc. All rights reserved.
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