Cisco Systems OL-7396-01 Manual De Usuario
23-9
ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter 23
Configuring the ATM Traffic-Shaping Carrier Module
Traffic-shaping Granularity Tables
Traffic-shaping Granularity Tables
This section lists the following granularity tables for configuring traffic-shaping rates on ATM
interfaces:
interfaces:
•
•
•
Table 23-4Best-Effort and VBR Shaping (Pcr-Only Mode) Rates for OC-3c (Cells Per Second),
page 23-28
page 23-28
•
•
Table 23-6Best-Effort and VBR Shaping (PCR-Only Mode) Rates for OC-12 (Cells Per Second),
page 23-47
page 23-47
•
The tables display shaping rates in cells per second and can be used for configuring connection traffic
table (CTT) rows. When configuring CTT rows, the traffic parameters are specified in kilobits per
second (kbps). By referring to the values listed in the tables, you can choose the rate in cells per second
that most closely matches the desired kbps rate for CTT rows.
table (CTT) rows. When configuring CTT rows, the traffic parameters are specified in kilobits per
second (kbps). By referring to the values listed in the tables, you can choose the rate in cells per second
that most closely matches the desired kbps rate for CTT rows.
shows rates for best-effort
connections and variable bit rate (VBR) connections using PCR-only mode.
shows rates for
VBR connections shaped using their PCR, SCR, and MBS parameters (the default VBR shaping mode).
The DS3, E3, E1, and T1 interfaces share the same values and are therefore represented in the same
granularity tables.
The DS3, E3, E1, and T1 interfaces share the same values and are therefore represented in the same
granularity tables.
The resource management software uses the following algorithm to convert the rates given in kbps to
cells per second. You can also use the algorithm as a guideline for determining the kbps value that must
be configured for the CTT rows.
cells per second. You can also use the algorithm as a guideline for determining the kbps value that must
be configured for the CTT rows.
In the following expression, kbps_val represents a rate specified in units of kbps and cps_val is the cell
per second equivalent of the specified kbps_val. Also, the following expressions use integer division and
the operator % represents modulus operations.
per second equivalent of the specified kbps_val. Also, the following expressions use integer division and
the operator % represents modulus operations.
intermediate=(kbps_val * 125);
if ((intermediate % 53) !=0)
cps_val = (intermediate / 53) + 1;
else
cps_val = (intermediate / 53);
Note
Observed traffic-shaping rates may vary as much as 2% from the values listed in these tables.
shows the DS3, E3, E1, and T1 rates for best-effort connections and VBR connections when
shaped using PCR-only mode.
Table 23-2 Best-Effort and VBR Shaping (PCR-Only Mode) Rates for DS3, E3, E1, and T1 (Cells Per
Second)
105510 105439 104946 104458 103974 103495 103021 102550 102084
101622 101164 100711 100261 99815
99374
98936
98502
98072