1. Cisco IOS IP Service Level Agreements Technical Overview
This presentation introduces Cisco IP Service Level Agreement (IP SLA), previously called Cisco Service Assurance Agent (SAA) in Cisco IOS Software.
Internet Technologies Division
November 2004

2. Agenda
Introduction
Cisco IOS IP Service Level Agreements (SLA) Overview
Use Cases for Cisco IOS IP SLAs
Cisco IOS IP SLAs for VoIP
Cisco IOS IP SLAs for IP/MPLS
Today, customers are adding voice, video, and other delay-sensitive applications (such as virtual private networks) to their IP data networks. The need for network performance monitoring has moved from being something used by service providers to something required by networks running converged IP services.
Having network monitoring capabilities in place helps networks verify service level guarantees, validate network performance, improve mean-time-to-restore, and reduce the time required for network troubleshooting.

3. VPNs with IOS-based Managed Services
Security
With Cisco IOS Firewall & Intrusion Prevention System
Routing
With Cisco Enhanced Interior Gateway Routing Protocol
Management
With Cisco IP SLAs
Corporate Intranet
Local or Direct
Dial ISP SP
Converged IP/MPLS Network PE
Remote Users/ Telecommuters
MPLS to IPsec/PE
VPN B
Head Office
Provider
Networks
Internet PE
Cable/DSL/ISDN ISP
Business Partner
Branch Office
Remote Access
Corporate Extranet

4. SLAs for IP/MPLS Networks
Cisco IOS IP SLAs’ operations measure per VPN
Allows measurements from a PE to CE routers
Cisco Exclusive
SP Converged IP/MPLS Network
P Router
Measure Either CE–PE or CE–CE Links
CRS-1
Enterprise
Site 2
Enterprise
Site 1
Measure Either CE–PE or CE–CE or
PE-PE Links
Service Provider: Improved and flexible SLA management
Enterprises: Access to comprehensive SLA reports
© 2003, Cisco Systems, Inc. All rights reserved.

5. Cisco IOS IP SLAs Advantages
VPN
SLAs are essential to VPN services
Quality of Service (QoS)-based measurements
Revenue for differentiated services
Brings IP service customer confidence
VoIP
Demonstrate how VoIP is working
Deploy with confidence
Enhanced customer satisfaction
Metrics useful for trouble shooting & and reducing down time
Business Applications
Assure delivery with network performance
Meet business objectives with guaranteed service levels
Assure network quality of service
Reduce downtime
Key Services Benefit from Cisco IOS IP SLA I II
III

6. Cisco IOS IP Service Level Agreements: A New Direction
Cisco solution that assures IP service levels, proactively verifies network operation, and accurately measures network performance
Comprehensive hardware support
Committed Cisco partner support
Cisco IOS Software, the world’s leading network infrastructure software
Enterprise and Small Medium Business
Service Providers
Understand Network
Performance &
Ease Deployment
Verify Service Levels
Verify Outsourced SLAs
Measure and provide
SLAs
Today, customers are adding voice, video, and other delay-sensitive applications (such as virtual private networks) to their IP data networks. The need for network performance monitoring has moved from being something used by service providers to something required by networks running converged IP services.
Having network monitoring capabilities in place helps networks verify service level guarantees, validate network performance, improve mean-time-to-restore, and reduce the time required for network troubleshooting.
Access
Enterprise Backbone
Enterprise Premise Edge
Service Provider Aggregation Edge
Service Provider Core
Cisco IOS Software

7. Cisco IOS IP SLAs Understanding IP Service Levels
Optimize IP business applications and services
Voice over IP, Video, and VPN
Reduce total cost of ownership
End to end service level measurements
Today, customers are adding voice, video, and other delay-sensitive applications (such as virtual private networks) to their IP data networks. The need for network performance monitoring has moved from being something used by service providers to something required by networks running converged IP services.
Having network monitoring capabilities in place helps networks verify service level guarantees, validate network performance, improve mean-time-to-restore, and reduce the time required for network troubleshooting.

8. Cisco IOS IP SLAs Benefits
OPTIMIZED APPLICATIONS & SERVICES
REDUCED TOTAL COST OF OWNERSHIP AND OpEx
Performance visibility
Prove service levels
Enhance Customer satisfaction
Enhance acceptance of business-critical services
Reduce deployment time
Lower mean time to restore and downtime
Proactive identification of issues enforces higher reliability
Measurements and Metrics
Proactive
Automated Intelligence
Continuous
Predictable Reliable
Today, customers are adding voice, video, and other delay-sensitive applications (such as virtual private networks) to their IP data networks. The need for network performance monitoring has moved from being something used by service providers to something required by networks running converged IP services.
Having network monitoring capabilities in place helps networks verify service level guarantees, validate network performance, improve mean-time-to-restore, and reduce the time required for network troubleshooting.

9. Cisco IOS IP SLAs Life Cycle
Understand network performance baseline Confidence to deploy
new IP services
and applications
Baseline network
performance Verify network readiness for new services with Cisco IOS IP SLA capabilities.
Assure application
and service deployment 2 1
Quantify results
Reduce deployment time
Prove service and application differentiation
Verify service levels
Reduce network down time
Manage demand for the network
Fine tune and optimize
Ongoing measurements to understand behavior
with proactive notification 3 4

10. Comprehensive Hardware Support
Enterprise & Aggregation/Edge
Core
Cisco IOS Software Release 12.2S
Cisco Series
Cisco Catalyst 6500; Cisco 7600 Series
Cisco Series
Cisco 7300 Series
Cisco 4500 Series
Cisco Series
Access
Cisco IOS Software Releases 12.3T and 12.4
Cisco 2900, 3550, & Series
Cisco 7200 & Series
Cisco 2600 Series
Cisco 3700 Series
Cisco 1700 Series
Cisco 800 Series

11. Defined Packet Size, Spacing Active Generated Traffic
Example: Multi-Protocol Measurement and Management with Cisco IOS IP SLAs
Applications
Availability
Network
Performance
Monitoring
VoIP
Monitoring
Service Level
Agreement
(SLA)
Monitoring
Network
Assessment
Multiprotocol
Label
Switching
(MPLS)
Monitoring
Trouble
Shooting
Measurement Metrics
Round Trip
Time
Packet
Loss
Network
Jitter
Dist. of
Stats
Connectivity
Protocols
Jitter
FTP
DNS
DHCP
DLSW
ICMP
UDP
TCP
HTTP
LDP
H.323
SIP
RTP
Radius
Video
Defined Packet Size, Spacing
COS and Protocol
IP Server
IP SLA
Cisco IOS
Software
IP Server
Source
MIB Data
Destination
IP SLA
Cisco IOS
Software
Active Generated Traffic
IP SLA
Cisco IOS
Software
Responder

12. Cisco IOS IP SLAs Uses and Metrics
*DATA
TRAFFIC
*VoIP
*SERVICE LEVEL AGREEMENT
*AVAILABILITY
**STREAMING
VIDEO
REQUIREMENT
Minimize Delay, Packet Loss
Verify QoS
Minimize Delay, Packet Loss, Jitter
Measure Delay, Packet Loss, Jitter
One-way
Connectivity testing
Minimize Delay, Packet Loss
IP SLA MEASURMENT
Jitter
Packet loss
Latency
per QoS
MOS Voice Quality Score
Enhanced accuracy
NTP
Connectivity tests to IP devices
Cisco IP SLA brings customers the ability to create a variety of end-to-end network performance tests based on clear measurement metrics for many network applications, assist in planning, and simplify and speed up network management tasks.
* Currently available
**Limited availability in 9/04; complete in CY’05

13. Cisco IOS IP SLAs Leading Performance Measurements
Cisco IOS IP SLA has been the most popular way to measure performance statistics (ie: latency, jitter, packet loss, and MOS) because:
Simplicity of solution, as compared to other technical solutions
High level of confidence
The packets are controlled
Cost scalable
Dedicated probes are not required
Cisco IOS IP SLA responder increases measurement accuracy
Not possible with ping or other dedicated probe testing

14. UDP Jitter Operation Example
= IP SLA UDP Jitter test packet – Operation 1 destination IP
= IP SLA UDP Jitter test packet – Operation 2 destination IP
Interval
Number of Packets
Frequency
Time
UDP Jitter default settings:
Frequency = 1 minute
Interval = 20 milliseconds
Number of Packets = 10

15. Cisco IOS IP SLAs Source and Responder
Source Router
Cisco IOS Software router that sends data from operation
Cisco IOS Software may or may not be the target
Some operations require the target to run the IP SLA responder
Stores results in MIB
Configuration for each operation (destination) device
Responder
Responds to IP SLA packets at destination
User defined UDP/TCP ports
IP SLA Control Protocol
MD 5 Authentication
Accurate measurements

16. UDP Jitter Operation Packet Stream
Send train of packets with
constant Interval
Receive train of packets at
Interval impacted by Network
IP Core
Responder
IP SLA
Add a receive time stamp, and calculate delta, the processing time.
Per-direction inter-packet delay (Jitter)
Per-direction packet loss
Average Round Trip Delay

17. The Responder takes 2 Timestamps (T2 & T3)
Source Router
Target Router
Responder T2 T1 T3 T4
D = T3 - T2
The Responder takes 2 Timestamps (T2 & T3)
Control Sequence Open up UDP ports.
IP SLA uses a control message on UDP port 1967 but the responder replies back to the control port on another UDP port number. Don’t know what it is but it is a high port number.
The control process is as follows. IP SLA sends control with type, and udp port and duration of probes, for this cycle.
Responder Ack control probe but on another port. Don’t know what the number is but it is high.
Responder then opens up udp port for the duration as instructed in control packet.
Responder received probes and then closes.
Responder is acknowledging probes as it receives them.
IP SLA Response Calculation
Source Router IP SLA processing delay =T5-T4
Responder processing delay = T3-T2
RTT is T5-T1 minus IP SLA and responder processing delays.
RTT = T5-(t1-dS+dT)
dT = Delta on Target Router, dS is delta on source.
Points to make about this slide.
IP SLA probe enters output interface queues as any other packet if you set precedent bits is will go to the back of the appropriate queue.
The dt and ds times are Router processing time these are the removed from all RTT and Jitter Calculations.
Clarification of Responder Time stamp process
When IP SLA or Responder is enabled device checks all IP packets to see if they are IP SLA probes packet is IP SLA probe interrupt is generated and the packet Router time stamped (T2) the IP packet this then queued.
The responder listens on UDP port when it is ready to process it will read IP queued packets. The responder timestamps then packet (T3) when it first receives the packet.
The difference in time T3-T2 is the time that the packet has waited in the IP queue for the responder to start processing the packet. This is idle time when the responder may be busy with another process or the router is busy and as the responder has normal priority other process will take precedence when the Router is busy.
The priorities are Critical, High, Normal and Low. IP SLA has normal.
Responder factors out destination processing time making results highly accurate
Responder allows for one-way measurements for latency, jitter, packet loss, and MOS

18. Cisco IOS IP SLAs Reaction Conditions
Reaction Trigger to Events
Can send SNMP traps for certain “triggering” events:
Connection Loss and Timeout
Round Trip Time Threshold
Average Jitter Threshold
Unidirectional packet loss, latency, jitter, MOS Scores
Can trigger another IP SLA operation for further analysis
Trigger
Immediate
Consecutive
X of Y times
Average Exceeded
Threshold
Violation
No Alert
Alert
Threshold
Violation
Alert
Enabling Reaction conditions set up in 2 parts.
1 Configure the threshold in the basic rtr configuration. Default is 5000ms
2 use the rtr reaction-configuration command to specify what you want react to.
A: Threshold, time-out, loss of connection in connection orientated protocols.
B: Threshold type immediate will react as soon as the threshold is crossed, consecutive will require a consecutive number of probes to exceed the threshold, xofy the last x out of y probes must exceed the threshold.
C: action-type what do you want the probe to do if a threshold is violated. Send a trap, trigger another SAA probe on the router.
D: threshold-falling send a trap for first crossing of threshold but don’t send any more until the lower threshold is crossed.
The configuration give does the following
Animation 1 &2 trap sent for first crossing.
Animation 3 no trap sent since not dropped below lower threshold
Animation 4 cross lower threshold rearm trap
Animation 5 cross upper threshold send second trap
100 ms
50 ms
Threshold
violation
Time
Resolution
Cisco IOS IP SLA, Technical, 9/04
Cisco Internal Use Only
© 2004 Cisco Systems, Inc. All rights reserved. 18

19. UDP Jitter One Way Latency
Availability X
12.2(11)T (Infra2)
12.2(14)S
12.1E
SNMP Support
12.2(2)T
APM
ICMP Path Jitter
Frame-Relay (CLI)
MPLS/VPN Aware
FTP Get
UDP Jitter One Way Latency
DLSw+
DHCP
DNS
HTTP
UDP Jitter
TCP Connect
UDP Echo
SSCP(SNA)
ICMP Echo Path
ICMP Echo
12.2(25)S
12.1(1)T 12.2
12.0(5)T 12.0(8)S
12.0(3)T
11.2
Feature/Release

20. Cisco IOS IP SLAs Partners
Cisco Network Management Solution
Cisco IP Solution Center
MPLS VPN and SLA Monitoring
Internetworking Performance Monitor
Enterprise performance measurements
THIRD PARTY PRODUCTS
Cisco partners, including HP and Concord Communications, have integrated IP SLA functions and metrics into their popular network performance tools.

21. CISCO IOS IP SLAs USE CASES

22. SLA Verification and Management
Customer obtains from Service Provider:
Availability
QoS
Jitter SLAs
Service Provider needs visibility in the Customer Edge, in order to commit to SLAs
Enterprise will verify SP SLAs by using access router edge to edge measurements
Enterprise may provide restricted Simple Network Management Protocol (SNMP) (RTT, Latency, QoS) visibility into Access router for Service Provider
Service Provider with restricted access can report SLA as a service back to the enterprise

23. Network Monitoring Cisco IOS IP SLA answers the following question:
What is the jitter, latency, or packet loss between any two points in the network?
IP Services can be simulated by specifying various packet sizes, ports, class of service, packet spacing, and measurement frequencies
Uni-directional and highly accurate measurements
Measurements per class of service to validate service differentiation for data, voice, and video
Cisco IOS IP SLA will identify an edge to edge network performance baseline and allow the user to understand trends and anomalies from the baseline

24. IP Network Readiness
Network assessment tool built into Cisco IOS Software
Simulate IP Services and verify how well they will work in the network
How well is QoS working in the network pre-deployment
Post deployment continued verification of network performance per IP service

25. Availability Monitoring
Cisco IOS IP SLA uses proactive monitoring for periodic, reliable, and continuous availability measurements
Connectivity measurements from Cisco router to router or Cisco router to server
Threshold notifications when end point is not available
What is the availability of a Network File System (NFS) server used to store business critical data from a remote site ?
Cisco IOS IP SLA UDP active measurement to specific server ports is used to test remote site to server connectivity
If server is unavailable, then traps can notify the network management system

26. Troubleshooting with Cisco IOS IP SLAs
Proactive notification of problems and issues based on threshold alerts
Testing edge to edge consistently and reliability will save time in finding and pin pointing network performance problem areas
Secondary activation of path operation (ie: path jitter) or activation of operations at a higher frequency to isolate and verify problem areas in the network

27. CISCO IOS IP SLAs FOR VoIP
Cisco IOS IP SLA can let you know if your network is ready to properly deploy VoIP.
It can also measure and monitor voice-over-IP performance and voice quality.

28. IP SLAs for Voice over IP
VoIP may be difficult to deploy when the network behavior is not well understood
Cisco IOS IP SLAs will verify network readiness and QoS
Measure critical performance for VoIP deployment
Real time warning of network performance degradation
IP SLA is universally available across Cisco IOS Software routers
So if intelligence at both endpoints is important – embedded at both the network and compute layer – as we look at the evolution of the intelligent network over time, as well as the evolution of the intelligent compute layer over time, we see the compute layer and the network layer working together to create this larger intelligent infrastructure.
The goal -- pervasive intelligence throughout your infrastructure.
Higher level functions (session, presentation, application) integrated into the network
Enabling applications/services on demand
Virtualization of services and applications through network APIs
Standard jitter, Packet loss,
latency
measurements
Voice quality
score
measurements
Call setup
measurements
Hardware-based
VoIP
measurements

29. IP SLA Network to Server Measurements
Cisco IOS IP SLAs for VoIP
Voice quality measurements between any two network points on any path
Continuous, reliable, predictable performance monitoring
Cisco IOS IP SLAs thresholds and hop-by-hop details isolate problems
IP SLA Network to Server Measurements
IP SLA WAN Measurements
A particularly valuable operation is UDP – User Datagram Protocol. It measures jitter, to understand the performance of VoIP and streaming media. The UDP operation sends out groups of packets with a known spacing and measures any changes in spacing that may occur. UDP monitors the variance in time spacing between data packets as they travel across a network. The UDP jitter measurement also includes the capability of Codec simulation and MOS Voice quality scoring. A A
PSTN IP
WAN
Branch
Headquarters
IP SLA End to End Measurements
Cisco IOS IP SLA, Technical, 9/04
Cisco Internal Use Only
© 2004 Cisco Systems, Inc. All rights reserved. 29

30. Cisco IOS IP SLAs for VoIP Features
November 2003 (Release 12.3(4)T)
VoIP Codec Simulations using Cisco IOS IP SLA active monitoring
Voice Quality Scoring
March 2003 (Release 12.3(7)T)
New Threshold traps, one-way packet loss, jitter, latency and MOS
Phase 1 – MOS voice quality scoring and VoIP codec simulation in the MIB and CLI
Phase 2 – New Proactive trapping mechanism for uni-directional measurements and MOS score
Phase 3- Call setup post dial delay and gatekeeper delay for H323/SIP
Phase 4 – Integration with VoIP gateway DSP’s to allow accurate voice quality and VoIP related statistics using active test calls.

31. CISCO IOS IP SLAs FOR IP/MPLS
Virtual private networks are a growing IP application.
IP SLA can monitor the connectivity of MPLS VPNs for one or more classes of service.

32. Cisco IOS IP SLAs Example United States, Service Provider
IP CLASS OF SERVICE
ONE-WAY DELAY
THROUGHPUT
JITTER
QoS BANDWIDTH PER AAPP
Priority Voice Traffic
< 80 ms
Packet loss < 5% less
< 35 ms
Max 75%
Real-Time Traffic – Video
Packet loss < 3%
60%
Priority Data Traffic
< 100 ms
Packet loss < 2%
30%
Best Effort Traffic
No target
10%
Newer IP SLAs are beginning to specify measurement of differentiated services.
Customers deploying IP services such as IP telephony, virtual private networking, IP video, and MPLS need to know these services going to work properly. Service level monitoring with standard, understandable metrics is required.
It’s vital for verifying a service provider’s SLAs and the information can be used to reduce a network’s mean-time-to-restore.
Jitter: telephony and multi-media conferencing
Packet Loss: telephony, multi-media conferencing, streaming media, low latency data
Delay: telephony, multi-media conferencing, streaming media

33. VPN SLAs and Performance Measurement
Cisco IOS a leader in IP/MPLS
How to measure an SLA within a specific VPN?
Cisco IOS IP SLA operations are vrf-aware and measure an SLA per VPN
Allows measurements from a PE or multi-vrf CE router
Releases 12.2(2)T, 12.2(20)S, and 12.0(26)S
(PE)
How do I provision a probe? (2 scenarios):
From CE to PE:
PE will receive the probe request from the CE in a VRF context
From PE to CE:
PE will look for destination IP address in the global routing table
Solution: Specify explicitly in which VRF PE must send the probe ->IOS 12.2(2)T
Provision from PE to CE: BW for Provision and retrieve IP SLA data doesn’t flow on the PE-CE link
CEs with VRFs Red, Blue and Yellow.

34. References References Cisco IOS IP SLAs www.cisco.com/go/ipsla
Add non-NetFlow paper