Chapter 6 Broadband
VMG1312-B10A User’s Guide
104
Multiplexing
There are two conventions to identify what protocols the virtual circuit (VC) is carrying. Be sure to
use the multiplexing method required by your ISP.
VC-based Multiplexing
In this case, by prior mutual agreement, each protocol is assigned to a specific virtual circuit; for
example, VC1 carries IP, etc. VC-based multiplexing may be dominant in environments where
dynamic creation of large numbers of ATM VCs is fast and economical.
LLC-based Multiplexing
In this case one VC carries multiple protocols with protocol identifying information being contained
in each packet header. Despite the extra bandwidth and processing overhead, this method may be
advantageous if it is not practical to have a separate VC for each carried protocol, for example, if
charging heavily depends on the number of simultaneous VCs.
Traffic Shaping
Traffic Shaping is an agreement between the carrier and the subscriber to regulate the average rate
and fluctuations of data transmission over an ATM network. This agreement helps eliminate
congestion, which is important for transmission of real time data such as audio and video
connections.
Peak Cell Rate (PCR) is the maximum rate at which the sender can send cells. This parameter may
be lower (but not higher) than the maximum line speed. 1 ATM cell is 53 bytes (424 bits), so a
maximum speed of 832Kbps gives a maximum PCR of 1962 cells/sec. This rate is not guaranteed
because it is dependent on the line speed.
Sustained Cell Rate (SCR) is the mean cell rate of each bursty traffic source. It specifies the
maximum average rate at which cells can be sent over the virtual connection. SCR may not be
greater than the PCR.
Maximum Burst Size (MBS) is the maximum number of cells that can be sent at the PCR. After MBS
is reached, cell rates fall below SCR until cell rate averages to the SCR again. At this time, more
cells (up to the MBS) can be sent at the PCR again.
If the PCR, SCR or MBS is set to the default of "0", the system will assign a maximum value that
correlates to your upstream line rate.
Summary of Contents for VWG1312-B10A
Page 2: ......
Page 8: ...Contents Overview VMG1312 B10A User s Guide 8 Troubleshooting 291 ...
Page 18: ...Table of Contents VMG1312 B10A User s Guide 18 ...
Page 19: ...19 PART I User s Guide ...
Page 20: ...20 ...
Page 34: ...Chapter 2 The Web Configurator VMG1312 B10A User s Guide 34 ...
Page 39: ...Chapter 4 Tutorials VMG1312 B10A User s Guide 39 7 Click Apply to save your settings ...
Page 79: ...79 PART II Technical Reference ...
Page 80: ...80 ...
Page 168: ...Chapter 9 Routing VMG1312 B10A User s Guide 168 ...
Page 186: ...Chapter 10 Quality of Service QoS VMG1312 B10A User s Guide 186 ...
Page 212: ...Chapter 13 Interface Group VMG1312 B10A User s Guide 212 ...
Page 228: ...Chapter 15 Firewall VMG1312 B10A User s Guide 228 ...
Page 234: ...Chapter 17 Parental Control VMG1312 B10A User s Guide 234 ...
Page 244: ...Chapter 19 Certificates VMG1312 B10A User s Guide 244 ...
Page 248: ...Chapter 20 Log VMG1312 B10A User s Guide 248 ...
Page 252: ...Chapter 21 Traffic Status VMG1312 B10A User s Guide 252 ...
Page 258: ...Chapter 24 IGMP Status VMG1312 B10A User s Guide 258 ...
Page 262: ...Chapter 25 xDSL Statistics VMG1312 B10A User s Guide 262 ...
Page 264: ...Chapter 26 User Account VMG1312 B10A User s Guide 264 ...
Page 270: ...Chapter 29 TR 064 VMG1312 B10A User s Guide 270 ...
Page 274: ...Chapter 30 Time Settings VMG1312 B10A User s Guide 274 ...
Page 280: ...Chapter 32 Logs Setting VMG1312 B10A User s Guide 280 ...
Page 298: ...Chapter 36 Troubleshooting VMG1312 B10A User s Guide 298 ...
Page 338: ...Appendix C Pop up Windows JavaScripts and Java Permissions VMG1312 B10A User s Guide 338 ...
Page 352: ...Appendix D Wireless LANs VMG1312 B10A User s Guide 352 ...
Page 368: ...Appendix G Legal Information VMG1312 B10A User s Guide 368 ...
Page 376: ...VMG1312 B10A User s Guide 376 Index ...