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User Guide for Cisco Security Manager 4.4
OL-28826-01
Chapter 59 Configuring Router Interfaces
PVCs on Cisco IOS Routers
PVCs on Cisco IOS Routers
Asynchronous Transfer Mode (ATM) is an International Telecommunication Union (ITU-T) standard
designed for the high-speed transfer of voice, video, and data through public and private networks using
cell relay technology. A cell switching and multiplexing technology, ATM combines the benefits of
circuit switching (constant transmission delay, guaranteed capacity) with those of packet switching
(flexibility, efficiency for intermittent traffic). An ATM network is made up of one or more ATM
switches and ATM endpoints, such as a Cisco IOS router.
There are three general types of ATM services, permanent virtual connections (PVCs), switched virtual
connections (SVCs), and connectionless service. PVCs allow direct and permanent connections between
sites to provide a service that is similar to a leased line. Advantages of PVCs are the guaranteed
availability of a connection and that no call setup procedures are required between switches. Each piece
of equipment between the source and destination must be manually provisioned for the PVC.
For more information about ATM PVCs, see:
•Understanding Virtual Paths and Virtual Channels, page 59-46
•Understanding ATM Service Classes, page59-47
•Understanding ATM Management Protocols, page 59-48
For more information about defining PVCs in Security Manager, see:
•Defining ATM PVCs, page59-50
•Defining OAM Management on ATM PVCs, page 59-53
Related Topics
•ADSL on Cisco IOS Routers, page 59-33
•SHDSL on Cisco IOS Routers, page 59-40

Understanding Virtual Paths and Virtual Channels

ATM networks are fundamentally connection oriented. This means that a virtual connection needs to be
established across the ATM network before any data transfer. Two types of ATM connections exist:
• Virtual path connections (VPCs), identified by a virtual path identifier (VPI).
• Virtual channel connections (VCCs), identified by the combination of a VPI and a VCI (virtual
channel identifier). PVCs are a type of VCC where a permanent connection is defined between two
sites.
Result The name generated by Security Manager from the information you
entered for the controller location. The name displayed in this field is
read-only.
Tip After closing this dialog box, you can edit t he generated name
in the SHDSL dialog box, if required.
Table59-20 Controller Auto Name Generator Dialog Box (Continued)
Element Description