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Chapter 6 Broadband
VMG5313-B10A/-B30A Series User’s Guide
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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.
The following figure illustrates the relationship between PCR, SCR and MBS.
Figure 27
Example of Traffic Shaping
Summary of Contents for VMG5313-B10A
Page 15: ...15 PART I User s Guide ...
Page 16: ...16 ...
Page 32: ...Chapter 2 The Web Configurator VMG5313 B10A B30A Series User s Guide 32 ...
Page 40: ...Chapter 4 Tutorials VMG5313 B10A B30A Series User s Guide 40 ...
Page 71: ...71 PART II Technical Reference ...
Page 72: ...72 ...
Page 78: ...Chapter 5 Network Map and Status Screens VMG5313 B10A B30A Series User s Guide 78 ...
Page 106: ...Chapter 6 Broadband VMG5313 B10A B30A Series User s Guide 106 ...
Page 162: ...Chapter 9 Routing VMG5313 B10A B30A Series User s Guide 162 ...
Page 180: ...Chapter 10 Quality of Service QoS VMG5313 B10A B30A Series User s Guide 180 ...
Page 198: ...Chapter 11 Network Address Translation NAT VMG5313 B10A B30A Series User s Guide 198 ...
Page 210: ...Chapter 14 Interface Group VMG5313 B10A B30A Series User s Guide 210 ...
Page 218: ...Chapter 15 USB Service VMG5313 B10A B30A Series User s Guide 218 ...
Page 232: ...Chapter 17 Firewall VMG5313 B10A B30A Series User s Guide 232 ...
Page 240: ...Chapter 19 Parental Control VMG5313 B10A B30A Series User s Guide 240 ...
Page 250: ...Chapter 21 Certificates VMG5313 B10A B30A Series User s Guide 250 ...
Page 296: ...Chapter 23 Voice VMG5313 B10A B30A Series User s Guide 296 ...
Page 300: ...Chapter 24 Log VMG5313 B10A B30A Series User s Guide 300 ...
Page 308: ...Chapter 27 xDSL Statistics VMG5313 B10A B30A Series User s Guide 308 ...
Page 318: ...Chapter 30 Remote Management VMG5313 B10A B30A Series User s Guide 318 ...
Page 322: ...Chapter 32 TR 064 VMG5313 B10A B30A Series User s Guide 322 ...
Page 332: ...Chapter 36 Log Setting VMG5313 B10A B30A Series User s Guide 332 ...
Page 336: ...Chapter 37 Firmware Upgrade VMG5313 B10A B30A Series User s Guide 336 ...
Page 352: ...Chapter 40 Troubleshooting VMG5313 B10A B30A Series User s Guide 352 ...
Page 354: ...354 ...
Page 374: ...Appendix B Wireless LANs VMG5313 B10A B30A Series User s Guide 374 ...
Page 390: ...Appendix E Legal Information VMG5313 B10A B30A Series User s Guide 390 ...