Billion Electric Company 5100S user manual Traffic Shaping, Configuring WAN Setup

PPTP supports on-demand, multi-protocol and virtual private networking over public networks, such as the Internet.

5.4 Traffic Shaping

Traffic Shaping is an agreement between the carrier and the subscriber to regulate the average rate and “burstiness” or fluctuation 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 1 Mbps gives a maximum PCR of 2415 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 a bursty, on-off traffic source that can be sent at the peak rate, and a parameter for burst-type traffic. SCR may not be greater than the PCR; the system default is 0 cells/sec.

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.

The following figure illustrates the relationship between PCR, SCR and MBS.

5.5 Configuring WAN Setup

To change your BIPAC 5100S’s WAN remote node settings, click WAN. The screen differs by the encapsulation.

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