Cisco IP SLA

Agenda

What is SLA? Overview of IP SLA What is Cisco IP SLA? Need for Cisco IP SLA? How it works? Implementation/Configuration of Cisco IOS SLA Troubleshooting Tips Benefits Hardware & Software Requirement

What is SLA?

• Stands for Service Level Agreement.

• This is a contractual obligation between a provider and it’s clients, spelling out the details of service.

• It may include downtime, bandwidth, latency, jitter,

responsibilities,…

• Specify a means of measuring each party's compliance to

the agreed terms.

IP SLA

• IP services enhance the efficiency of the network, and help businesses to achieve key objectives and gain a competitive advantage. Service levels are crucial because they affect the performance of IP services and business-critical applications. SLAs between Service Providers and customers or between corporate Enterprise IT departments and end-users are intended to provide service guarantees and validate network performance on an ongoing basis

What is Cisco IP SLA?

• IP SLA is an acronym for IP Service Level Agreements. Cisco IP SLA is an embedded, synthetic performance-monitoring tool to measure service performance from the network perspective

• Cisco IP Service Level Agreement (IP SLA) is software built into Cisco IOS for monitoring application response times with synthetic packets between two network end-points

Why Cisco IP SLA?

• Many network administrators have not implemented best practices for measuring IP services and service levels

• When network performance is poorly understood, there is a higher chance of network downtime and greater potential for decreased network reliability

• 55% of companies only identify some of their network traffic – Lack in understanding the network behavior

Continued…

• 40% of companies delay launching new applications due to network performance concerns

• Application response times are at the heart of application delivery management

• Customers demand guaranteed, reliable network services for business-critical applications

• Effectively measuring and monitoring IP services in real time contributes to increased profits, effective troubleshooting, and faster deployment of network applications

Why Cisco IP SLA?

There are some methods to measure and monitor network performance.

Like:

• Wait for problem to happen, and customer to complain ->

Reactive approach• Manually -> Boring approach• Special hardware probes -> The expensive approach

Why Cisco IP SLA?

• Drawbacks of these Approaches: Requires additional hardware. New software, protocols. Additional configuration skills. Eventually adding a new vendor, support contract ,…

Why Cisco IP SLA?

• Hence, there is a need to proactively verify network operation, and to accurately measure network performance

The Idea behind IP SLAs• If you have a running Cisco IOS router, turn it into an active probing device -> The smart approach• Reuse your current equipment and enhance existing network management applications.

How it works?

• Cisco IOS IP SLAs measure performance by sending one or more packets to a destination IP device or a Cisco router

• After the destination device receives the packet, and depending on the type of Cisco IOS IP SLAs operation, the device will respond with time-stamp information for the source to make the calculation on performance metrics.

Implementation of Cisco IOS SLA

On Destination 1. Enable the Cisco IOS IP SLA Responder on Destination Router(config)# ip sla monitor responder On Soure2. Configure the required Cisco IOS IP SLAs operation type.3. Configure any options available for the specified Cisco IOS IP SLAs operation

type.4. Configure threshold conditions, if required.5. Schedule the operation to run, then let the operation run for a period of time to

gather statistics.6. Display and interpret the results of the operation using Cisco IOS CLI or an

NMS system with SNMP.

Commands & its purpose..

Command or Action Purpose ip sla monitor operation-number Begins configuration for an IP SLAs operation and

enters IP SLA monitor configuration mode.

type echo protocol ipIcmpEcho {destination-ip-address | destination-hostname} [source-ipaddr {ip-address | hostname} | source-interface interface-name]

Defines an ICMP Echo operation and enters IP SLA Monitor ICMP Echo configuration mode.

frequency seconds (Optional) Sets the rate at which a specified IP SLAs operation repeats.

exit Exits IP SLA Monitor ICMP Echo configuration mode and returns to global configuration mode.

ip sla monitor schedule operation-number [life {forever | seconds}] [start-time {hh:mm[:ss] [month day | day month] | pending | now | after hh:mm:ss] [ageout seconds] [recurring]

Configures the scheduling parameters for an individual IP SLAs operation.

exit (Optional) Exits global configuration mode and returns to privileged EXEC mode.

Commands & its purpose..

Command or Action Purpose

show ip sla monitor statistics To view and interpret the results of an IP SLAs operation

show ip sla monitor configuration [operation-number]

(Optional) Displays configuration values including all defaults for all IP SLAs operations or a specified operation.

Cisco IOS IP SLAs Operations and Applications

Measurement Capability Key Applications

UDP Jitter • Round-trip delay, one-way delay, one-way jitter, one-way

packet loss

• One-way delay requires time synchronization between

the Cisco IOS IP SLAs source and target routers

Most common operations for networks that carry voice or video traffic, such as IP

backbones

UDP Echo Round-trip delay Accurate measurement of response time of UDP traffic

UDP Jitter for VoIP • Round-trip delay, one-way delay, one-way jitter, one-way

packet loss

• VoIP codec simulation G.711 ulaw, G.711 alaw, and

G.729a

• MOS and ICPIF voice quality scoring capability

• One-way delay requires time synchronization between

the Cisco IOS IP SLAs source and target routers

Useful for VoIP network monitoring

Cisco IOS IP SLAs Operations and Applications

Measurement Capability Key Applications

TCP Connect Connection time Server and application performance monitoring

Domain Name System (DNS) DNS lookup time DNS performance monitoring, troubleshooting

Dynamic Host ConfigurationProtocol (DHCP)

Round-trip time to get an IP address

Response time to a DHCP server

FTP Round-trip time to transfer a file FTP get performance monitoring

Cisco IOS IP SLAs Operations and Applications

Measurement Capability Key Applications

HTTP Round-trip time to get a Web page Web site performance monitoring

Internet Control MessageProtocol (ICMP) Echo

Round-trip delay Troubleshooting and availability measurement

using ICMP ping

ICMP Path Echo Round-trip delay for the full path Troubleshooting

ICMP Path Jitter Round-trip delay, jitter, and packet loss for the full path

Troubleshooting

Data Link Switching Plus(DLSw+)

Peer tunnel performance DLSw peer tunnel performance monitoring

IP SLAs UDP Jitter Operation

• The IP SLAs UDP jitter operation was primarily designed to diagnose network suitability for real-time traffic applications such as voice over IP (VoIP), video over IP, or real-time conferencing.

• The following example shows the configuration of the IP SLAs UDP jitter operation number 1 that will start now run indefinitely

ip sla monitor 1type jitter dest-ipaddr 172.29.139.134 dest-port 5000 num-packets

1000frequency 30ip sla monitor schedule 1 life 300 start-time now

UDP Echo Operation

• The UDP echo operation measures end-to-end response time between a Cisco router and devices using IP. UDP is a network layer (Layer 3) Internet protocol that is used

• The following example shows the configuration of an IP SLAs operation type of UDP echo that will start immediately and run indefinitely.

ip sla monitor 5type udpEcho dest-ipaddr 172.29.139.134 dest-port 5000frequency 30!ip sla monitor schedule 5 start-time now life forever.

HTTP Operation

• The HTTP operation measures the round-trip time (RTT) between a Cisco device and an HTTP server to retrieve a web page.

• The following example shows the configuration of an IP SLAs operation type of HTTP GET that will start immediately and run indefinitely. This operation will retrieve the home page from the

www.cisco.com website.ip sla monitor 8type http operation get url http://198.133.219.25frequency 10!ip sla monitor schedule 8 life forever start-time now

TCP Connect Operation

• The IP SLAs TCP Connect operation measures the response time taken to perform a TCP Connect

• operation between a Cisco router and devices using IP.• The following example shows the configuration of an IP SLAs

operation type of TCP Connect that will start immediately and run indefinitely.

ip sla monitor 9type tcpConnect dest-ipaddr 172.29.139.132 dest-port 5000frequency 10!ip sla monitor schedule 9 life forever start-time now

FTP Operation

• The FTP operation measures the round-trip time (RTT) between a Cisco device and an FTP server to retrieve a file.

• The following example shows the configuration of an IP SLAs operation type of FTP to retrieve a file named test.cap. The FTP operation number 10 is scheduled to start immediately and run indefinitely.

ip sla monitor 10type ftp operation get url ftp://username:password@hostip/test.capfrequency 30!ip sla monitor schedule 10 life forever start-time now

DNS Operation

• The DNS operation measures the difference between the time taken to send a DNS request and receive a reply. DNS is used in the Internet for translating names of network nodes into addresses. The IP SLAs DNS operation queries for an IP address if you specify a host name, or queries for a host name if you specify an IP address.

• The following example shows the configuration of an IP SLAs operation type of DNS to find the IP address of the hostname cisco.com. The DNS operation number 11 is scheduled to start immediately and run indefinitely.

ip sla monitor 11type dns target-addr www.cisco.com name-server 172.20.2.132frequency 60exitip sla monitor schedule 11 life forever start-time now

ICMP Echo Operation

• The ICMP Echo operation measures end-to-end response time between a Cisco router and any devices using IP. Response time is computed by measuring the time taken between sending an ICMP Echo request message to the destination and receiving an ICMP Echo reply.

• The following example shows the configuration of the IP SLAs ICMP Echo operation number 6 that will start immediately and run indefinitely.

ip sla monitor 6 type echo protocol ipIcmpEcho 172.29.139.134 source-ipaddr

172.29.139.132 frequency 300 ip sla monitor schedule 6 life forever start-time now

ICMP Echo Operation

• ICMP Echo Operation (Output)• Router#sh ip sla stat 6

• Round Trip Time (RTT) for Index 6

• Latest RTT: 1 milliseconds

• Latest operation start time: *10:54:59.551 PST Wed Jun 28 2006

• Latest operation return code: OK

• Number of successes: 1

• Number of failures: 0

• Operation time to live: 3593 sec

Troubleshooting Tips

• If the IP SLAs operation is not running and generating statistics, add the verify-data command to the configuration of the operation (while configuring in IP SLA monitor mode) to enable data verification. When enabled, each operation response is checked for corruption.

• Note: Use the verify-data command with caution during normal operations because it generates unnecessary overhead.

• Use the debug ip sla monitor trace and debug ip sla monitor error commands to help troubleshoot issues with an IP SLAs operation.

Benefits

• We already own it. Just turn it on. IP SLA is resident within IOS.

• Cisco IOS IP SLAs monitoring

• – Provides service level agreement monitoring, measurement, and verification.

• Network performance monitoring

– Measures the jitter, latency, or packet loss in the network.

– Provides continuous, reliable, and predictable measurements.

• IP service network health assessment

• – Verifies that the existing QoS is sufficient for new IP services.

Benefits

• Edge-to-edge network availability monitoring– Provides proactive verification and connectivity testing of network

resources (for example,indicates the network availability of an NFS server used to store business critical data from a remote site).

• Troubleshooting of network operation– Provides consistent, reliable measurement that immediately

identifies problems and saves troubleshooting time.• Voice over IP (VoIP) performance monitoring• Multiprotocol Label Switching (MPLS) performance monitoring

and network verification

Hardware & Software Requirement

• IOS Routers: Available on all platforms from the small 800 up to

the 12000.

• Catalyst Switches: 2900, 3500, 3700, 4000 (SUP4), 6000 (MSFC

or MWAM)

• Included in IP feature set since 11.3 and up to 12.2, and 12.3M

(included).

• Starting release 12.3T and all 12.4, the IP Voice or upper feature

set will be required.

Thank you