11-6
C
HAPTER
11: ATM N
ETWORKS
Permanent Virtual Circuits
PVCs are established via network management and are left up indefinitely.
Both point-to-point and point-to-multipoint connections can be estab-
lished.
Virtual Paths and
Virtual Channels
As in traditional LAN packets, the header of each ATM cell contains
addressing information. However, rather than a specific destination address,
each cell header contains two fields, the VPI and the VCI, that specify the
virtual connection (VC) over which the cell should be forwarded. See
Figure 11-3.
Figure 11-3
Virtual Channels and Virtual Paths
The VPI and VCI establish only the connections between two ATM entities,
not the end-to-end connection of the user to the switch.
A virtual channel is a connection between two or more end-points. All
communications proceed along the same VC, which preserves cell sequence
and provides a specific quality of service.
Figure 11-4 shows the relationship among virtual paths (VPs), virtual
channels (VCs), and virtual channel connections (VCCs).
VP
VCs
Transmission path VP
VP
VP
VP
VP
VCs
VCs
Summary of Contents for LANPLEX 2500
Page 1: ...LANPLEX 2500 OPERATION GUIDE Part No 801 00344 000 Published November 1996 Revision 03...
Page 14: ......
Page 18: ...1 4 CHAPTER 1 LANPLEX MANAGEMENT AND ADMINISTRATION OVERVIEW...
Page 78: ...III Chapter 9 FDDI Overview and Implementation Chapter 10 FDDI Networks FDDI TECHNOLOGY...
Page 97: ...IV Chapter 11 ATM Networks ATM TECHNOLOGY...
Page 116: ...V Appendix A SNMP MIB Support Appendix B Technical Support APPENDIXES...