ACS TPO Profile Configuration Mode Commands


ACS TPO Profile Configuration Mode Commands
 
 
The ACS TPO Profile Configuration Mode is used to configure TPO profiles.
 
note_smallImportant: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
 
end
Exits the current configuration mode and returns to the Exec mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
end
Usage
Use this command to return to the Exec mode.
 
exit
Exits the current mode and returns to the parent configuration mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
exit
Usage
Use this command to return to the parent configuration mode.
 
http
This command configures HTTP parameters.
Product
TPO
Privilege
Security Administrator, Administrator
Syntax
http { ad-filter display { no-text | text-only text_only_string | text-with-click text_with_click_string } | compression | optimize-compressed-page | params { ad-filter display bgcolor bg_color_code | compression level compression_level | url-rewrite prefix url_rewrite_prefix } | prevent-server-compression | url-rewrite }
default http { ad-filter display | compression | optimize-compressed-page | params { ad-filter display bgcolor | compression level | url-rewrite prefix } | prevent-server-compression | url-rewrite }
no http { compression | optimize-compressed-page | params ad-filter display bgcolor | prevent-server-compression | url-rewrite }
default
Configures the default setting for the specified parameter.
Default:
compression: Disabled
url-rewrite prefix: urlrewrite
url-rewrite: Disabled
no
Deletes TPO configuration for the specified parameter.
ad-filter display { no-text | text-only text_only_string | text-with-click text_with_click_string }
Enables HTTP Advertisement Filter, and configures the options:
no-text: Specifies to block advertisements. Mobile client users see the “cannot display image” icon (usually an X mark) instead of a blocked advertisement. Users cannot view the blocked advertisements even if they want to.
text-only text_only_string: Specifies to block advertisements. Mobile client users will see a placeholder frame instead of each blocked advertisement. Each placeholder frame contains the text specified here along with the advertisement’s URL. Users cannot view the blocked advertisements even if they want to.
text_only_string must be an alpha and/or numeric string of 1 through 255 characters in length.
text-with-click text_with_click_string: Specifies to block advertisements. Mobile client users will see a placeholder frame instead of each blocked advertisement. Each placeholder frame contains the text specified here along with the advertisement’s URL. To view the blocked advertisements users must click the placeholder frames.
text_with_click_string must be an alpha and/or numeric string of 1 through 255 characters in length.
compression
Enables HTTP compression for Web pages.
Default: Disabled
optimize-compressed-page
Enables uncompressing compressed Web pages to apply other HTTP optimization techniques.
If the Web server responds to the mobile client with a compressed Web page, in order to apply other HTTP optimization techniques that maybe enabled, TPO can uncompress the Web page, apply the other HTTP optimizations, recompress the Web page and then send it to the mobile client.
Default: Disabled
params { ad-filter display bgcolor bg_color_code | compression level compression_level | url-rewrite prefix url_rewrite_prefix }
Configures HTTP compression optimization parameters:
ad-filter display bgcolor bg_color_code: For the HTTP Advertisement Filter feature, specifies color code for the advertisement placeholder frames’ background.
bg_color_code must be a hex string of 1 through 6 characters in length.
compression level compression_level: Enables HTTP compression, and specifies the compression level.
compression_level specifies the HTTP compression level, and must be an integer from 1 through 9. The higher the compression_level, the better the compression but more the CPU and memory utilization.
Default: 6
url-rewrite prefix url_rewrite_prefix: Enables HTTP URL rewrite, and specifies the HTTP URL rewrite prefix.
url_rewrite_prefix specifies the HTTP URL rewrite prefix, and must be an alpha and/or numeric string of 8 through 32 characters in length.
When embedded URLs are returned, the embedded URLs are replaced. For example, when “http://www.foo.com/xxx” is in the response, the URL is replaced with “http://ip-address/<url_rewrite_prefix>/www.foo.com/xxx”. In this example, the DNS client resolves “www.foo.com” and puts that resolution as “ip-address”. When the subscriber later does a GET, that request is modified as:
URL: STRING/www.foo.com/xxx — will be changed to be just xxx
Host: ip-address — will be changed to be “www.foo.com”
Default: urlrewrite
prevent-server-compression
Specifies TPO (to manipulate the HTTP request) to prevent server compression at the Web server.
This enables TPO to receive uncompressed data from the Web server, on which it can apply other HTTP optimization techniques, and then compress and send the data to the mobile client.
Default: Disabled
url-rewrite
Enables URL Rewrite feature.
The URLs that are embedded in response pages are rewritten. This eliminates the need for the subscriber to perform DNS to resolve those URLs. See the url-rewrite option.
Default: Disabled
Usage
Use this command to configure TPO’s HTTP parameters.
Example
The following command configures HTTP compression optimization parameter to level 3:
http params compression level 3
 
p2p-detected
This command allows to disable/continue TPO optimizations when a P2P flow is detected.
Product
TPO
Privilege
Security Administrator, Administrator
Syntax
p2p-detected { cease-tpo | continue-tpo }
default p2p-detected
default
Configures the default setting.
Default: continue-tpo
cease-tpo
Specifies to disable TPO optimizations when a flow is detected as P2P.
note_smallImportant: In this release, only TPO TCP optimizations are disabled. Disabling HTTP optimizations will be supported in a future release.
continue-tpo
Specifies to continue TPO optimizations when a flow is detected as P2P.
Usage
Use this command to disable/continue TPO optimizations when a P2P flow is detected.
While switching TPO profiles, if P2P flow is detected, TPO will be ceased/allowed based on the current TPO profile.
Example
The following command disables all TPO TCP optimizations when a P2P flow is detected:
p2p-detected cease-tpo
 
tcp
This command configures TCP parameters.
Product
TPO
Privilege
Security Administrator, Administrator
Syntax
tcp { bandwidth { bandwidth_kbps | dynamic } | buffer-size { downlink | uplink } buffer_size_kb | congestion-control { basic | vegas | westwood-plus } | fast-retransmit-dupacks { duplicate_acks | dynamic } | handoff-optimization | initial-window { initial_window | dynamic bdp-percent bdp_percent | rfc5681 } | mss mss | pacing | rto { retrans-backoff { 1.0 | 1.5 | 2.0 } | rttvar-scaling scaling_factor } }
default tcp { bandwidth | buffer-size { downlink | uplink } | congestion-control | fast-retransmit-dupacks | handoff-optimization | initial-window | mss | pacing | rto { retrans-backoff | rttvar-scaling } }
no tcp { bandwidth | handoff-optimization | pacing }
no
Removes/disables the specified configuration.
default
Configures the default setting for the specified parameter.
Default:
bandwidth: No known bandwidth limit
downlink: 128 KB
uplink: 32 KB
mss: 536 bytes
pacing: Disabled
rto:
bandwidth { bandwidth_kbps | dynamic }
Specifies bandwidth, which is used by TCP to optimize the data transfer rate.
bandwidth_kbps specifies the maximum available bandwidth for a TCP flow, in kbps, and must be an integer from 1 through 100000.
dynamic specifies to use a value computed dynamically at runtime.
Default: No known bandwidth limit, same as no tcp bandwidth command.
buffer-size { downlink | uplink } buffer_size_kb
Specifies the socket send and receive buffer size for uplink/downlink traffic.
downlink: Specifies the maximum amount of data that can be buffered inside TCP Proxy in downlink direction for each TCP connection. When the amount of data buffered in TCP Proxy in downlink direction reaches this limit, TCP Proxy sets receive window size in TCP header to 0 towards TCP server.
uplink: Specifies the maximum amount of data that can be buffered inside TCP Proxy in uplink direction for each TCP connection. When the amount of data buffered in TCP Proxy in uplink direction reaches this limit, TCP Proxy sets receive window size in TCP header to 0 towards TCP client.
buffer_size_kb specifies the buffer size, in KB, and must be an integer from 4 through 8192.
congestion-control { basic | vegas | westwood-plus }
Specifies the TCP congestion-control algorithm to use.
basic: Specifies to use the basic TCP congestion-control algorithm.
vegas: Specifies to use the Vegas TCP congestion-control algorithm.
westwood-plus: Specifies to use the Westwood-plus TCP congestion-control algorithm.
Default: basic
fast-retransmit-dupacks { duplicate_acks | dynamic }
Specifies the number of duplicate ACKs required for fast retransmission.
duplicate_acks: Specifies the number of duplicate ACKs that will trigger a fast-retransmit of the missing segment. After the specified number of duplicate ACKs is received, it is assumed that the segment was lost and is retransmitted.
duplicate_acks must be an integer from 1 through 10.
Default: 3
In 12.0 and earlier releases, this keyword specifies to dynamically change the number of duplicate ACKs required for fast retransmission based on the number of in-flight packets (one-third of the in-flight packets, subject to a minimum of two). This enables to eliminate spurious retransmissions when packet reordering in the network is high.
In 12.2 and later releases, this keyword specifies to dynamically change the number of duplicate ACKs required for fast retransmission based on the number of in-flight packets, and controls the actions taken on D-SACK detection.
If the dynamic keyword is not configured, D-SACK detection takes place, but no action is taken.
note_smallImportant: In case the client does not support SACK, the behavior falls back to as described for 12.0 and earlier releases.
For information on D-SACK Support, refer to the Traffic Performance Optimization Administration Guide.
handoff-optimization
Specifies to enable handoff detection and relevant processing by TCP.
Default: Disabled
initial-window { initial_window | dynamic bdp-percent bdp_percent | rfc5681 }
Specifies the initial window size for a TCP session.
initial_window: Specifies the initial-window in units of MSS segments.
initial_window must be an integer from 1 through 255.
dynamic bdp-percent bdp_percent: Specifies to use a dynamically computed value at runtime, which is calculated as a percentage of bandwidth-delay product (BDP).
bdp_percent must be an integer from 1 through 100.
For dynamic setting, the bandwidth information is derived from the bandwidth command, and the delay is calculated using the SYN-ACK exchange. If the bandwidth information is not available, this configuration does not have any effect (i.e., behavior will be same as default setting).
rfc5681: Specifies to use a value recommended by RFC 5681, which will vary from 2 through 4 based on MSS.
Default: rfc5681
mss mss
Specifies the maximum segment size (MSS), in bytes.
mss must be an integer from 248 through 65535.
Default: 536 bytes
pacing
Enables TCP Pacing.
Under some conditions (typically at the end of fast-recovery) a single ACK is received, which acknowledges huge amount of data. Because of this, the sliding-window suddenly shifts to the right, causing the sender to burst huge amount of data into the network at one shot and this typically triggers a tail-drop (loss of series of packets) at the bottleneck router. Also, huge data bursts can occur due to lot of other factors such as ACK compression and so on. TCP Pacing causes the sender to evenly distribute window of data over an entire RTT.
Default: Disabled
rto { retrans-backoff { 1.0 | 1.5 | 2.0 } | rttvar-scaling scaling_factor }
Specifies Retransmission Timeout (RTO) settings.
Specifies the RTO back-off factor. Once retransmission timeout RTO fires for a packet, TCP will retransmit that packet and set the RTO to be a factor X, specified here, of the previous RTO.
Default: 2.0
1.0: Specifies to use backoff factor 1.0.
1.5: Specifies to use backoff factor 1.5.
2.0: Specifies to use backoff factor 2.0.
rttvar-scaling scaling_factor
Specifies the scaling factor for Round Trip Time Variation (RTTVAR).
The configured scaling factor is used as a power of 2, so values of 0 through 4 correspond to 1, 2, 4, 8, and 16. RTO is calculated in TCP using following formula:
RTO = SRTT + K*RTTVAR
where:
As wireless networks exhibit high RTT variation, the value of K is made configurable. The value of K decides the extent to which RTO timer depends on RTT variance. If RTT variance is higher, then K should be higher.
scaling_factor must be an integer from 0 through 4.
Default: 2
Usage
Use this command to configure TPO’s TCP parameters.
Example
The following command configures the initial window size for a TCP session to 100:
tcp initial-window 100
 
 

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