Note: To perform this task from PolicyCenter, you must first select a configuration in the Configurations window. Then select the Setup tab from the right pane of this window, and proceed to step 2 of the procedure below.

Header Overhead (bytes)
Number of bytes that are added to each packet to account for WAN protocol header overhead

Link Overhead (ppt)
Number of parts per thousand* by which packet sizes are increased to account for link overhead. This adjustment is useful for links that do bit stuffing. (Bit stuffing is the practice of adding bits to a stream of data. Bit stuffing is required by many network and communications protocols, for example to prevent data from being interpreted as control information.)

* to be more precise, it’s actually parts per 1024

Small MSS Link Speed
Link speeds slower than this value will force the use of smaller MSS (maximum segment size)
Prevents PacketWise from changing the MSS on large WAN links

Maximum Segment Size (Inbound)
Maximum segment size of TCP packets on Inbound flows. This setting can help avoid packet fragmentation when using VPN and not being able to support 1500-byte packets (the default size) through the VPN tunnel.

Maximum Segment Size (Outbound)
Maximum segment size of TCP packets on Outbound flows

Clamp Early Retransmission (Inbound)
Number of milliseconds delay for clamping early retransmission time-out on Inbound packets. Puts a maximum on retransmit time.

Clamp Early Retransmission (Outbound)
Number of milliseconds delay for clamping early retransmission time-out on Outbound packets

Asymmetric Flows Only
By turning on this setting, PacketWise will automatically assume all flows are asymmetric and stop TCP Rate Control. In topologies where there are a large percentage of asymmetric flows, this may be more efficient than attempting to apply regular rate control. In addition to disabling rate control, turning on this setting disables all layer 7 classification activities. (PacketWise must see traffic in both directions in order to classify layer 7.)

Bridge PassThru
With Bridge PassThru enabled, the PacketShaper forwards packets that have a source and destination MAC address on the same side of the unit. When Bridge PassThru is disabled and traffic shaping is enabled, the PacketShaper drop packets that have source and destination MAC addresses on the same side.

Caching of IP address-based classes
Cache IP address-based classes on the inside or outside of the PacketShaper. Change this setting to outside to increase performance of classification if the majority of IP addresses in manually created classes are on the outside, rather than the inside.

Display "503 - Service unavailable" Messages
Control the display of the "503 - Service unavailable" server error message when a connection is refused because of admission control (such as a never-admit policy). When set to off, the "503 - Service unavailable" message will be customized with the text "This message is sent by Packeteer PacketShaper." When set to on, PacketWise will perform a TCP reset and drop the HTTP request; the error message will likely be "The attempt to load http://... failed."

Enable Support for LFN
When enabled, this setting improves performance on Long Fat Networks (LFN) which require larger TCP window sizes. An LFN is a long distance network with large bandwidth and long delay; for example, high-capacity satellite channels are LFNs.

Policy flow limits for all classes
Enables/disables the policy flow limit feature. When enabled, PacketWise will enforce all policy flow limits that have been set on traffic classes. When disabled, all policy flow limits will be ignored. For additional information, see policy flowlimit.

Non-IP Flows
The number of new non-IP connections of a given type that must be identified within a one-minute time frame before PacketWise creates a class

Identifiable Services
The number of new connections of an identifiable service to a port less than or equal to 1024 that must be identified within a one-minute time frame before PacketWise creates a class

Dynamic Ports
The number of new connections of an identifiable service to a port greater than 1024 that must be identified within a one-minute time frame before PacketWise creates a class

Static Ports
The number of new connections to a static port within a one-minute time frame before PacketWise creates a Port_#### class in the DiscoveredPorts folder

It may be necessary to increase this value on Internet link deployments to prevent excessive number of DiscoveredPorts classes being created. If you don’t want any Port_#### classes discovered, set this variable to its maximum value.

Active
The number of seconds a dynamic partition will be retained after an established flow has sent packets

Note: If no other user needs a dynamic partition, the partition will be retained indefinitely.

Idle
The number of seconds a dynamic partition will be retained after an established flow has not sent or received packets

Note: If no other user needs a dynamic partition, the partition will be retained indefinitely.

Reserved for Static
The number of partitions reserved for static partitions; all other partitions can be used for dynamic or static partitions (applicable to PacketShaper 1200, 1400, and 1550 only)

Host Entries
The maximum number of hosts and partners that can be defined to use the compression facility

* 0 indicates that the default system limit will be used; the system limit depends on the amount of memory installed in the unit

Enable packing
When packing is enabled, multiple packets are combined into a single "super packet," in order to save on overhead. Packing increases compression rates because less data is being sent out on the wire.

Note: On very busy links, packing doesn't cause much latency because the packets are bundled and sent off quickly. On less active links, Xpress may have to wait to get enough packets in a bundle, possibly creating application performance problems. If you are experiencing latency, try lowering the packing hold time or disabling it altogether.

Packing hold time
Maximum number of milliseconds packets will be held for packing. When PacketShaper Xpress receives a packet, it is held up to the maximum packing hold time (10ms by default), waiting to be combined with additional packets. After that time expires, Xpress compresses all the accumulated packets into a super packet and sends it out.

Transparent trigger threshold
The number of consecutive retransmissions of a packet before Xpress disables the compression tunnel and sends packets in the clear (uncompressed). The tunnel will resume normal operation after it gets an acknowledgment for the retransmitted packets; if acknowledgment is not received before the Tunnel shutdown threshold is reached, the tunnel will be shut down.

Tunnel shutdown threshold
The maximum consecutive retransmissions of a packet before a compression tunnel is shut down

Allow/Exclude inside hosts on list
Compression hosts are designated with the setup compression hosts add command. By default, the specified hosts are the ones allowed to use compression. If you want the specified hosts to be the ones excluded from compression, you can change the setting of the Allow/Exclude inside hosts on list variable.

If allow is selected, only listed inside hosts are eligible for compression. If exclude is selected, inbound traffic destined to the listed hosts is not compressed, but all other inside hosts are eligible for compression.

Allow/Exclude outside hosts on list
Compression hosts are designated with the setup compression hosts add command. By default, the specified hosts are the ones allowed to use compression. If you want the specified hosts to be the ones excluded from compression, you can change the setting of the Allow/Exclude ouside hosts on list variable.

If allow is selected, only listed outside hosts are eligible for compression. If exclude is selected, outbound traffic destined to the listed hosts is not compressed but all other outside hosts are eligible for compression.

Allow/Exclude PacketShapers on partner list
Compression partners are designated with the setup compression partners command. By default, the specified partners are the ones allowed to use compression. If you want the specified partners to be the ones excluded from compression, you can use the Allow/Exclude PacketShapers on partner list to do so.

If allow is selected, Xpress creates compression tunnels only with the listed PacketShapers. If exclude is selected, Xpress does not establish compression tunnels with the listed PacketShapers; only PacketShapers not listed have compression tunnels established.

Differentiated Services Interoperability
Preserve TOS (Type-of-Service) IP header values on compressed packets. When this option is enabled, TOS values will be preserved on IPComp packets. When it is disabled, TOS values will not be preserved on compressed packets.

Reapply TOS header value
Reapply network-modified TOS IP header values to decompressed packets. When this option is enabled, the decompressing Xpress unit will compare the original TOS value of the compressed packets to the TOS value in the IPComp packet’s IP header. If the network modified the TOS value of the IPComp packet, Xpress will apply this modified TOS value to the original packets as they are decompressed.

Note: The Differentiated Services Interoperability variable must also be enabled.

Graph Timeout
The maximum number of seconds a graph can take to generate in the browser interface; if the graph takes longer to generate than this value, a system time-out error message will appear.

Note: Increasing this setting can make the browser interface appear to "freeze" while PacketWise is generating some of the more complex graphs. Sometimes the browser will not display the page until all of the graphs are generated.

Browser HTTP Acceleration
Enable/disable GZIP compression of HTTP content sent from the PacketShaper to a web browser. Enabling this setting improves performance of the PacketWise browser interface on slow links. Supported on Internet Explorer 6.0; not supported on IE 5.5.

Registered Events
The maximum number of events that can be registered

User-Defined Events
The maximum number of events that can be user-defined

Extended SNMP Version
Enable/disable the extended SNMP trap for user events. When this variable is turned on, there will be an additional field in the trap that indicates the type of situation that triggered the trap. The field indicates violated (when the threshold was exceeded) or rearm (when the re-arm value was crossed).

Intermediate FDR
Enable/disable the intermediate flow detail records feature. When this variable is enabled, PacketWise emits intermediate FDRs at the interval specified by the flowRecordsIntermediateTimeout variable.

Note: Enable the intermediate flow detail records feature only when using a suitably-instrumented collector, such as Cisco-based Netflow-5 collectors. ReportCenter version 3.1 and earlier ignore intermediate FDRs.

Intermediate FDR Timeout
Number of milliseconds between generation and sending of intermediate flow detail records when traffic is present

Packeteer-P Packets
Enable/disable emission of Packeteer-P packets to Packeteer flow detail record collectors. Packeteer-P packets contain statistics that are not related to particular flows, but rather provide information about utilization on the PacketShaper at the time flows are recorded. If this variable is enabled, Packeteer-P records are sent after each UDP flow record packet is sent to Packeteer-1 or Packeteer-2 collectors (not more than once per minute).

Packeteer-P Timeout
Number of seconds between generation and sending of Packeteer-0 flow records.

Packeteer-0 Packets
Enable/disable emission of Packeteer-0 packets to Packeteer flow detail record collectors. Packeteer-0 packets are mapping messages that allow collectors to decipher Packeteer-related information in the FDRs they receive. For example, in the FDR’s ClassID field, a value identifies the traffic class. In order for the collector to understand what class is actually associated with the ID, it uses the class map — a list that contains each traffic class on the unit along with the identifying number assigned to each class. If this variable is enabled, Packeteer-0 mappings are sent out approximately once each hour. Note that this variable needs to be enabled only if the collector does not know this information through other means.

Packeteer-0 Timeout
Number of seconds between generation and sending of Packeteer-0 flow records.

Reset Packeteer 1/2 Counters
Controls whether or not the counter fields in FDR packets are reset with each intermediate FDR sent

Note: This variable only affects Packeteer-1 and Packeteer-2 format FDRs: counter fields are always reset in the NetFlow-5 format.

Enable Latency Calculations
Enable/disable the calculation of latency for VoIP metrics. When this variable is enabled, PacketWise collects data that measure latency for VoIP flows.

Notes: Latency can only be measured between PacketShapers with latency calculations enabled (on). This variable was in the Miscellaneous category in PacketWise 7.5.0, and was moved into the VoIP Metrics category in PacketWise 7.5.1.

Latency Probe Send Interval
Number of seconds between the issuance of VoIP latency probes that measure VoIP metrics, enabled by the enableLatency variable.

Note: This variable was in the Miscellaneous category in PacketWise 7.5.0, and was moved into the VoIP Metrics category in PacketWise 7.5.1.

Synthetic Transaction Timeout (Read)
Number of seconds after which a synthetic transaction will end when the response received is incomplete

Note: This variable is not available on PacketShaper ISP models.

Synthetic Transaction Timeout (Write)
Number of seconds after which a synthetic transaction will be canceled if the server fails to respond to a request

Note: This variable is not available on PacketShaper ISP models.

Maximum Frame Routes
The maximum number of route entries PacketWise can import from a FRAD or ATM routing table

Note: This variable is not available on the PacketShaper 1200 and 1400 Lite models.

Link State Mirroring
Enable/disable link state mirroring. With link state mirroring, PacketWise will bring down the second port of a NIC pair if the first goes down. This feature allows each PacketShaper to sit between a WAN router and a switch without blocking detection of switch outages by the router. Link state mirroring is automatically enabled when direct standby is enabled and the redundant management port is connected.

Note: Link state mirroring is not active on the LEM being used for the direct link; this allows you to disconnect the redundant management port without impacting connectivity. However, link state mirroring is disabled when the redundant management link is disconnected. This variable cannot be configured via PolicyCenter.

Estimate Packet Exchange Time
Enable/disable the calculation of packet exchange time. When this variable is disabled, the Pkt Exch column on the Monitor Traffic page will not appear, RTM will not be available, and the packet exchange time and RTM measurement variables will always have a value of 0.

After disabling the Estimate Packet Exchange Time variable, you should reset the unit.

Note: This variable is not available on the PacketShaper 1200 model.

Enable Support For SSHv1
Enable/disable support for Secure Shell version 1 (SSH v1) for secure access to the PacketShaper (this variable is available in PacketWise 7.4.1 and higher). When SSH v1 support is disabled, secure access is restricted to SSH v2.

Note: Changes to this variable require a unit reset to take effect.