RoHC Profile Compression
Configuration Mode Commands
The RoHC Profile Compression
Configuration Mode is used to configure RoHC (Robust Header Compression)
Compressor parameters. RoHC is not supported on GGSN.
IMPORTANT:
The availability of
commands, keywords and variables in this mode are dependent on platform
type, product version, and installed license(s).
context-timeout
Context timeout in
seconds.
Syntax
context-timeout seconds
default context-timeout
default
Returns the command
to its default value.
seconds
Specifies the context
timeout value (in seconds) as an integer from 0 through 100.
Default: 20
Usage:
Use this command to
set the context timeout.
Example:
The following command
sets the context timeout to 10 seconds:
context-timeout-period 10
end
Exits the current
configuration mode and returns to the Exec mode.
Privilege:
Security Administrator,
Administrator
Usage:
Use this command to
return to the Exec mode.
exit
Exits the current
mode and returns to the parent configuration mode.
Privilege:
Security Administrator,
Administrator
Usage:
Use this command to
return to the parent configuration mode.
ipid-history-size
Specifies the number
of IP-IDs of previously sent packets to store. An IP ID is a 16-bit
header field that stores IPv4 Identification information.
Syntax
ipid-history-size number
default ipid-history-size
default
Returns the command
to its default value.
number
Specifies the number
of IP IDs to store as an integer from 1 through 32.
Default: 8
Usage:
Use this command to
set the number of IP IDs to store in the history.
Example:
The following command
sets the history size to 24 IP-IDs:
ipid-history-size 24
max-jitter-cd
Specifies the upper
boundary of jitter expected on the communication channel between
the compressor and decompressor.
Syntax
max-jitter-cd num_ms
default max-jitter-cd
default
Returns the command
to its default value.
num_ms
Specifies the number
of milliseconds for the maximum jitter setting as an integer from
0 through 999999999.
Default: 150
Usage:
Use this command to
set the maximum amount of jitter allowed on the communication channel
between compressor and decompressor.
Example:
The following command
sets the jitter limit to 1000 ms (1 second):
max-jitter-cd 1000
max-sliding-window
Specifies the width
of the sliding window for W-LSB (Windows-based Least Significant
Bits) encoded values.
Syntax
max-sliding-window size
default max-sliding-window
default
Returns the command
to its default value.
size
Specifies the size
of the sliding window as an integer from 1 through 1000.
Default: 6
Usage:
Use this command to
set the size of the sliding window used to compute jitter for W-LSB encoded
values.
Example:
The following command
sets the sliding window size to 500:
max-sliding-window 500
multiple-ts-stride
Enables or disables
the use of repeated transmission of RTS_STRIDE for timer-based
compression.
Syntax
[ no ] multiple-ts-stride
no
Disables the use of
repeated transmission of RTS_STRIDE for time-based compression.
Usage:
Use this command to
enable or disable a gateway’s ability to repeatedly transmit RTS_STRIDE
for timer-based compression.
new-context-blocking-time
Specifies the time
period in seconds for blocking the establishment of new contexts
after the compressor has received a feedback reject.
Syntax
new-context-blocking-time seconds
default context-timeout
default
Returns the command
to its default value.
seconds
Specifies the context
blocking time (in seconds) as an integer from 0 through 100.
Default: 20
Usage:
Use this command to
set the context blocking time after the compressor has received
a feedback reject.
Example:
The following command
sets the context blocking time to 10 seconds:
new-context-blocking-time 10
num-pkts-ts
Specifies the number
packets per RTP timestamp (TS).
Syntax
num-pkts-ts num_pkts
default num-pkts-ts
default
Returns the command
to its default value.
num_pkts
Specifies the number
of packets for the timestamp as an integer from 0 through 999.
Default: 6
Usage:
Use this command to
set the number of packets for each RTP timestamp (TS).
Example:
The following command
sets the number of packets per timestamp to 50:
num-pkts-ts 50
num-pkts-u-mode
Specifies the number
of packets sent when operating in U-Mode (unidirectional mode).
Syntax
num-pkts-u-mode num_pkts
default num-pkts-u-mode
default
Returns the command
to its default value.
num_pkts
Specifies the number
of packets sent in U-Mode as an integer from 0 through 999.
Default: 1
Usage:
Use this command to
set the number of packets sent when in U-Mode.
Example:
The following command
sets the number of packets for U-Mode to 50:
num-pkts-u-mode 50
num-updates-ir
Configures the number
of IR (Initiation and Refresh state) updates.
Syntax
num-updates-ir num_pkts
default num-updates-ir
default
Returns the command
to its default value of 4.
num_pkts
Specifies the number
of IR updates as an integer from 0 through 999.
Default: 4
Usage:
Use this command to
set the number of IR updates.
Example:
The following command
sets the number of IR updates to 30:
num-updates-ir 30
optimistic-repeats
Specifies the number
of repeated packets to send to the decompressor. For transition
from the FO (First Order) to the SO (Second Order) state, the compressor
should be confident that the decompressor has all the parameters
needed to decompress according to a fixed pattern.The compressor
obtains its confidence about decompressor status by sending several
packets with the same information according to the lower compression
state. If the decompressor receives any of these packets, it is
in sync with the compressor.
Syntax
optimistic-repeats num_pkts
default optimistic-repeats
default
Returns the command
to its default value.
num_pkts
Specifies the number
of packets to repeat with the same information to assure synchronization
with the decompressor.
num_pkts must
be an integer from 0 through 10.
Default: 6
Usage:
Use this command to
set the number of packets to repeat to the decompressor to assure synchronization
before transition states.
Example:
The following command
sets the number of repeated packets to 5:
optimistic-repeats 5
rtp-sn-p
Specifies the value
of p in RTP SN (RTP Sequence Number) calculation. Least Significant
Bits (LSB) encoding is used for header fields whose values are usually
subject to small changes. With LSB encoding, the k least significant
bits of the field value are transmitted instead of the original
field value, where k is a positive integer. After receiving k bits,
the decompressor derives the original value using a previously received
value as reference (v_ref). The scheme is guaranteed to
be correct if the compressor and the decompressor each use interpretation
intervals as follows:
- In which the original
value resides
- And in which the original
value is the only value that has the exact same k least significant
bits as those transmitted.
The interpretation
interval can be described as a function:
f(v_ref, k).
Let f(v_ref, k) = [v_ref -
p, v_ref + (2^k - 1) - p]
Where p is an integer.
Syntax
rtp-sn-p p_value
default rtp-sn-p
default
Returns the command
to its default value.
p_value
Specifies the value
of p in the RTP SN calculation as an integer from 0 through 999.
Default: 6
Usage:
Use this command to
set the value for p when performing the RTP SN calculation.
Example:
The following command
sets the value of p to 100:
rtp-sn-p 100
rtp-sn-p-override
Enables an override
of p in the RTP SN calculation. This
is disabled by default.
Syntax
[ default | no ] rtp-sn-p-override
default
Returns the command
to its default value of disabled.
no
Disables overriding
p in RTP SN calculation.
Usage:
Use this command to
enable an override of p in RTP SN calculation.
Example:
The following command
enables the override of p in the RTP SN calculation:
rtp-sn-p-override
rtp-time-stride
Sets the time interval
used for one TS (RTP Time Stamp) stride. This interval is used when
timer-based encoding is enabled.
Syntax
rtp-time-stride num_ms
default rtp-time-stride
default
Returns the command
to its default value.
num_ms
Specifies the number
of milliseconds to use for TS_STRIDE as an integer from
0 through 999999999.
Default: 20
Usage:
Use this command to
set the length of the TS_STRIDE in milliseconds.
Example:
The following command
sets TS_STRIDE to 100ms:
rtp-time-stride 100
rtp-ts-deviation
Sets the maximum percentage
of deviation allowed for input RTP packets for timer-based compression.
Syntax
rtp-ts-deviation percentage
default rtp-ts-deviation
default
Returns the command
to its default value of 25.
percentage
Specifies the maximum
percentage of deviation allowed for input RTP packets for timer-based
compression as an integer value from 0 through 100.
Default: 25
Usage:
Use this command to
set the maximum percentage of deviation allowed for input RTP packets
for timer-based compression.
Example:
The following command
sets the percentage to 30:
rtp-ts-deviation 30
rtp-ts-stride
Specifies the amount
by which TS (RTP time stamp) is incremented. This value is used
for Scaled RTP TS encoding.
Syntax
rtp-ts-stride num_ms
default rtp-ts-stride
default
Returns the command
to its default value of 160.
num_ms
Specifies the number
of milliseconds to use incrementing TS as an integer from 0 through 999999999.
Default: 160
Usage:
Use this command to
set the amount by which TS is incremented for Scaled RTP TS encoding.
Example:
The following command
sets amount by which TS is incremented to 100ms:
rtp-ts-stride 100
sliding-window-ts
Sets the sliding window
used to compute jitter.
Syntax
sliding-window-ts size
default sliding-window-ts
default
Returns the window
to its default value of 4.
size
Specifies the size
of the sliding window as an integer from 1 through 1000.
Default: 4
Usage:
Use this command to
set the size of the sliding window used to compute jitter for the current
RoHC profile.
Example:
The following command
sets the sliding window size to 500:
sliding-window-ts 500
total-jitter-ipv4
Specifies the total
jitter allowed after compression for IPv4.
Syntax
total-jitter-ipv4 time
default total-jitter-ipv4
default
Returns the command
to its default value of 270.
time
Specifies the time
interval to use (in milliseconds) as an integer from 0 through 999999999.
Default: 270
Usage:
Use this command to
set the jitter limit after compression.
Example:
The following command
sets the jitter after compression limit to 900 ms:
total-jitter-ipv4 900
total-jitter-ipv6
Specifies the total
jitter allowed after compression for IPv6.
Syntax
total-jitter-ipv6 time
default total-jitter-ipv6
default
Returns the command
to its default value 580.
time
Specifies the total
jitter interval allowed (in milliseconds) as an integer from 0 through 999999999.
Default: 580
Usage:
Use this command to
set the jitter limit after compression.
Example:
The following command
sets the jitter after compression limit to 900 ms:
total-jitter-ipv6 900
unimode-timeout-to-fo-state
Specifies the time
period in seconds before falling back to the FO (First Order) state.
Syntax
unimode-timeout-to-fo-state num_ms
default unimode-timeout-to-fo-state
default
Returns the command
to its default value of 3.
num_ms
Specifies the timeout
period (in seconds) as an integer from 0 through 10.
Default: 3
Usage:
Use this command to
set the timeout before falling back to the FO state when in Unimode.
Example:
The following command
sets the fall back timeout to 2 seconds:
unimode-timeout-to-fo-state 2
unimode-timeout-to-ir-state
Specifies the time
period in seconds before falling back to the IR (Initiation and Refresh)
state.
Syntax
unimode-timeout-to-ir-state num_ms
default unimode-timeout-to-ir-state
default
Returns the command
to its default value of 5.
num_ms
Specifies the timeout
period in seconds as an integer from 0 through 20.
Default: 5
Usage:
Use this command to
set the timeout before falling back to the IR state when in Unimode.
Example:
The following command
sets the fall back timeout to 3 seconds:
unimode-timeout-to-ir-state 3
use-calculated-rtp-time-stride
Overrides the configured
value of rtp-time-stride with a calculated value.
Syntax
[ default | no ] use-calculated-rtp-time-stride
default
Returns the command
to its default value of enabled.
no
Disables the use of
calculated RTP time stride override.
Usage:
This command overrides
the configured value of rtp-time-stride with a calculated value.
Example:
The following command
overrides the configured value of rtp-time-stride.
use-calculated-rtp-time-stride
use-calculated-rtp-ts-stride
Overrides the configured
value of rtp-ts-stride with a calculated value.
Syntax
[ default | no ] use-calculated-rtp-ts-stride
default
Returns the command
to its default value of enabled.
no
Disables the use of
calculated RTP TS time stride override.
Usage:
This command overrides
the configured value of rtp-ts-stride with a calculated value.
Example:
The following command
overrides the configured value of rtp-ts-stride.
use-calculated-rtp-ts-stride
use-ipid-override
Enables or disables
overriding the IP-ID (IPv4 Identification header field).
Syntax
[ default | no ] use-ipid-override
default
Returns the command
to its default value of disabled.
no
Disables the IP-ID
override.
Usage:
Use this command to
enable overriding of the IP-ID.
Example:
The following command
enables the IP-ID override feature:
use-ipid-override
The following command
disables the IP-ID override feature:
no use-ipid-override
The following command
also disables the IP-ID override feature:
default use-ipid-override
use-optimized-talkspurt
Enables or disables
the use of optimized talkspurt.
Syntax
[ default | no ] use-optimized-talkspurt
default
Returns the command
to its default value of enabled.
no
Disables the use of
optimized talkspurt.
Usage:
Use this command to
enable and disable the use of optimized talkspurt
Example:
The following command
enables the use of optimized talkspurt:
use-optimized-talkspurt
The following command
disables the use of optimized talkspurt:
no use-optimized-talkspurt
use-optimized-transience
Enables or disables
the use of optimized transience.
Syntax
[ default | no ] use-optimized-transience
default
Returns the command
to its default value of enabled.
no
Disables the use of
optimized transience.
Usage:
Use this command to
enable or disable the use of optimized transience.
Example:
The following command
enables the use of optimized transience.
use-optimized-transience
The following command
disables the use of optimized transience.
no use-optimized-transience
use-timer-based-compression
Enables or disables
timer-based compression of the RTP time stamp (TS) at the compressor.
Syntax
[ default | no ] use-timer-based-compression
default
Returns the command
to its default value of enabled.
no
Disables the use of
timer-based compression.
Usage:
Use this command to
enable or disable the use of timer-based compression.
Example:
The following command
enables the use of timer-based compression.
use-timer-based-compression
The following command
disables the use of timer-based compression.
no use-timer-based-compression
use-uncomp-profile
Enables or disables
the use of the Uncompressed Profile (0x0000) if required at the
compressor.
Syntax
[default | no ] useS-uncomp-profile
default
Returns the command
to its default value of disabled.
no
Disables the use of
the Uncompressed Profile.
Usage:
Use this command to
enable or disable the use of the Uncompressed Profile.
Example:
The following command
enables the use of the Uncompressed Profile.
use-uncomp-profile
The following command
disables the use of the Uncompressed Profile.
no use-uncomp-profile