- Service Assurance Agent
Service Assurance Agent (SAA) is an active measurement technology initially developed by Cisco. SAA is sometimes also referred to in conversation as Application Performance Monitor (APM) or Response Time Responder (RTR).
Note: This technology was previously known as the Response Time Reporter (RTR), then as the Service Assurance Agent (SAA) and has since been renamed to
IP SLAs .What SAA does
With SAA, routers and/or switches perform periodic measurements. These include:
*
HTTP Get
* FTP downloads
* DNS lookups
* UDP Echo (forVoIP Jitter & MOS)
* DLSw (SNA Tunneling protocol)
* DHCP lease requests
* TCP Connect
* ICMP Echo (remote ping)The exact number and type of available measurements depends on the IOS version. SAA enables building truly distributed performance collection systems. SAA is very widely used in service provider networks to generate time-based performance data. It is typically used together with
SNMP andNetflow which generate volume-based data. SAA is often used to generate data which is need byIP SLAs .Important things to know
* For SAA measurements needs a device with SAA support. SAA is supported on Cisco routers and switches since IOS version 12.1. Other vendors like Juniper or Enterasys support SAA on some of their devices.
* SAA measurements and data collection can be configured via the console (command line) or via SNMP.
* When using SNMP, both read and write community strings are needed.
* The SAA voice quality feature was added starting with IOS version 12.3(4)T. All versions after this including 12.4 mainline contain the MOS and ICPIF voice quality calculation for the SAA UDP jitter measurement.Tools support
You need a software tool to plot SAA charts. SAA is widely supported by tools from different vendors. These include:
* [http://www.prolan.ru/solutions/diagnostics/npmanalyst/index.html NPM Analyst]
* [http://www.infosim.net Infosim StableNet]
* [http://www.watch4net.com/ Watch4Net APG]
* [http://www.openview.hp.com/products/ovpi_net/prod_ovpi_net_0002.html HP OV Performance Insight]
* [http://www.cisco.com/en/US/products/sw/cscowork/ps1008/prod_release_note09186a008007fb4d.html Cisco Works IPM]
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