Cisco Systems Cisco IOS XR manual GL-13

Glossary

V

VCSEL

vm

vertical cavity surface emitting laser.

A vm file is a Cisco IOS XR software file that can be installed from ROM Monitor mode. A vm file is typically used to install the Cisco IOS XR software when the software has not yet been installed or has been corrupted.

VPN	Virtual Private Network. Enables IP traffic to travel securely over a public TCP/IP network by
	encrypting all traffic from one network to another. A VPN uses “tunneling” to encrypt all information
	at the IP level.

W

WRED	Weighted Random Early Detection. Queueing method that ensures that high-precedence traffic has
	lower loss rates than other traffic during times of congestion.

X

XML

XML agent

Extensible Markup Language. A standard maintained by the World Wide Web Consortium (W3C) that defines a syntax that lets you create markup languages to specify information structures. Information structures define the type of information, for example, subscriber name or address, not how the information looks (bold, italic, and so on). External processes can manipulate these information structures and publish them in a variety of formats. XML allows you to define your own customized markup language.

A process on the router that is sent XML requests by XML clients and is responsible for carrying out the actions contained in the request and returning an XML response back to the client. The XML Agent for CORBA is an example of an XML agent provided on the Cisco CRS-1 router.

XML client	An external application that sends an XML request to the router and receives XML responses to those
	requests.
XML operation	A portion of an XML request that specifies an operation that the XML client would like the XML agent
	to perform.
XML operation	The router code that carries out a particular XML operation including parsing the operation XML,
provider	performing the operation, and assembling the operation XML response
XML request	An XML document sent to the router containing a number of requested operations to be carried out.
XML response	The response to an XML request.
XML schema	An XML document specifying the structure and possible contents of XML elements that can be
	contained in an XML document.

	Cisco IOS XR Getting Started Guide
OL-10957-02		GL-13