PVCTXCTL(8) BSD System Manager's Manual PVCTXCTL(8)NAMEpvctxctl — display or control ATM PVC transmitter parameters
SYNOPSISpvctxctl interface [[vpi:]vci]
pvctxctl interface [vpi:]vci [-n] [-b max-bandwidth] [-j [vpi:]vci]
[-p pcr]
DESCRIPTIONpvctxctl displays or controls the shaper parameters of an ATM VC. When a
shaper value is specified, pvctxctl sets a shaper to an ATM VC. pvctxctl
works for a PVC sub interface pvc(4) as well as a real ATM interface
en(4).
For a real ATM interface, the specified VC should be assigned beforehand
by route(8).
For a sub interface, pvctxctl assigns the specified VC to the sub inter‐
face. If another VC is already assigned to the sub interface, the old VC
is invalidated.
Availability of shapers, the number of hardware shaper channels, and
accuracy of shaping are all device dependent. For example, ENI Midway
chip has 8 shaper channels but the driver reserves one for non-shaping
VCs.
The options are as follows:
interface The interface parameter is a string of the form “name unit”,
for example, “en0”.
[vpi:]vci The VC number to which the shaper is assigned. When the VPI
number is omitted, VPI number 0 is assumed. For example, to
assign a shaper to VPI=0 and VCI=201, the following forms can
be used: "201", "0xc9", "0:201", "0:0xc9".
-b max-bandwidth
The PCR parameter can be specified also in “bits per second”.
The rate is the rate of AAL5 frame and the PCR is calculated
by the following form:
PCR = max-bandwidth / 8 / 48
“K” and “M” can be used as a short hand of “000” and “000000”
respectively. For example, “45M” means “45Mbps” or PCR value
“117187”.
-j [vpi:]vci
The join parameter is intended for VP shaping. The VC shaper
channel is shared with the existing VC, which means the sum
of the cell rates never exceeds the maximum PCR among the
shared VCs. On the other hand, when the shaper channel is
not shared, the sum of the cell rates could be the sum of the
PCRs.
For example, if two VCs (say 201 and 202) share a 45Mbps VP,
use:
# pvctxctl en0 201 -b 45M
# pvctxctl en0 202 -b 45M -j 201
-n This parameter is only for a sub interface. Use NULL encap‐
sulation instead of LLC/SNAP.
-p pcr The PCR (Peak Cell Rate) parameter specifies the peak cell
rate in "cells per second". If PCR value "0" is specified,
no shaper is assigned, which means cells are sent at full-
speed of the link. If PCR value “-1” is specified, the cor‐
responding VC is invalidated.
SEE ALSOen(4), ifconfig(8), pvcsif(8), route(8)BUGS
A real ATM interface and a sub interface require different sequences to
set a shaper. For example, to assign a 45Mbps shaper to VC 201 (0xc9) of
en0:
# ifconfig en0 10.0.0.1
# route add -iface 10.0.0.2 -link en0:3.0.0.c9
# pvctxctl en0 0xc9 -b 45M
For a shadow interface,
# pvcsif en0 # creates pvc0
# ifconfig pvc0 10.0.0.1 10.0.0.2
# pvctxctl pvc0 201 -b 45M
BSD December 29, 1997 BSD