First Steps Xpress

8/6/2019 First Steps Xpress

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First Steps to Using the

PacketShaper® CompressionModule



TABLE OF CONTENTS

OVERVIEW ................................................................................................................1Feature Requirements and Limitations.............................................................................................................2

CONFIGURING COMPRESSION ................................................................................. 3Direct Standby .............. ................ .............. ............... .............. ............... ............... ................ ............... ............ 5

DISPLAYING COMPRESSION REPORTS ....................................................................6Viewing the Compression Summary................................................................................................................6

Viewing the Top Ten Compressed Applications..............................................................................................9

Problems? ............. ............... ............... .............. ............... .............. .............. ............... ................ ............... .....10



First Steps to Using the Compression Module 1

Overview

The compression module allows you to increase the virtual size of WAN bandwidth and

improve application performance. By integrating compression technologies with traffic

management, PacketWise ensures that the increased virtual WAN pipe is not consumed by

aggressive, non-mission-critical applications that burst to consume any bandwidth given to

them. In addition, the effective throughput of the mission-critical traffic can also increase,

providing a double benefit. Packeteer’s shaping module protects mission-critical traffic,

contains recreational and unsanctioned traffic, and smooths peaks in bursty traffic, while

the compression module provides greater throughput and network capacity. The

compression module is also known as the Xpress feature.

PacketShapers identify other units with compression modules on the network and

dynamically setting up compression tunnels between the units. A tunnel is automatically

set up when traffic is sent between PacketShapers, as shown in the following diagram.

Tunnel A is created for the traffic between the clients in Branch Office A and the servers at

the main site. Likewise, Tunnel B is created for the traffic between the clients in BranchOffice B and the main site servers. Tunnel C is created for the traffic between the clients in

Branch Office A and the clients in Branch Office B.

The PacketShaper does not attempt to compress all traffic. Because the PacketShaper is

application intelligent, it is able to identify each traffic flow and compress only the flows

that are likely to achieve useful gains. Previously compressed traffic (such as streaming

media) and encrypted data are examples of non-compressible traffic. The ability to apply

appropriate compression algorithms to different applications is built into Packeteer’s

compression engine. With this design, you can choose, for each application, the appropriate

algorithm that will yield the best compression ratio, with minimal latency.

✍ Note: If you want to evaluate the compression feature before purchase, you can use

the Compression Estimator. See PacketGuide for more information.

CorporateWAN

Main Site Servers

Main SiteLAN

Internet

PacketShaper PacketShaper PacketShaper PacketShaper

Tunnel A Tunnel B

Tunnel C

Branch Office A Branch Office B

CorporateWAN

CorporateWAN

CorporateWAN



2 First Steps to Using the Compression Module

Feature

Requirements and

Limitations

The list below describes the requirements and limitations for the compression module:

• Compression is supported on the following PacketShaper models. Make sure your

model has the minimum amount of memory listed below:

• To use compression on existing PacketShaper units, you need to purchase a

compression module software key from Packeteer, and install it onto each unit.• The compression module is not available on PacketShaper ISP models.

• If you are using compression with Packeteer’s direct standby feature, the LEM

that is used for direct connection cannot be configured for compression.

• If a PacketShaper with compression is deployed in a Virtual Private Network

(VPN), the (private) address space on both sides of the VPN tunnel between the

PacketShaper units needs to be separate and unique in order to allow the two units

to set up a compression tunnel.

• Only packets with unicast destination addresses are sent through the compression

tunnel; broadcast and multicast packets are not sent through the tunnel.

• Non-IP protocol traffic (such as IPX and SNA) is not sent through the

compression tunnel.

PacketShaper ModelsMinimum Memory

Requirement

1200 256 MB

1550 256 MB

1700 256 MB

2500 512 MB

Note: A Memory Upgrade Kit

may be required.

3500 1 GB

6500 512 MB

7500 2 GB

8500 1 GB

9500 2 GB

10000 2 GB




3. For each PacketShaper device (main or LEM) you want to use for compression, fill in

the following information:

4. Click apply changes to update the settings.

5. From the Choose Setup Page list, select basic.

6. In the Compression field, select on to enable compression.

7. Click apply changes.

8. Log in to each PacketShaper on your network and repeat the above steps.

As soon as compression is enabled and compressible traffic goes through your

PacketShaper, compression tunnels will automatically be set up with other compression-

enabled units that are detected on the network. PacketShaper creates tunnels and

compresses data when the following conditions are true:

• Compression is enabled.

• The flow is destined for a host on the other side of a compression-enabled

PacketShaper.

• The flow belongs to a compressible service. Services that are unlikely to achieve

useful gains from compression are not compressed by default. VoIP and encrypted

data are examples of traffic that are not compressed.

Field Description

IP Address IP address to assign to the interface; each interface

must have a unique address. Note that this address

is used by the compression feature and is not for

managing the PacketShaper. An Xpress-IP address

can NOT be the same as the unit’s management

address if you have a LEM installed or if you have

enabled the Dedicated Management Port feature. It

should not be the same address as the secondary

customer portal address.

Packeteer strongly recommends that you do not use

the management IP address for an Xpress-IP

address.

Net Mask Subnet mask

Gateway IP address of the router; leave blank or enter none

if there is no gateway. The gateway is required if the

compression partner is not on the same subnet.




• The two PacketShapers are configured outside port to outside port. For example:

Direct Standby PacketShapers can be used in a redundant configuration using Packeteer’s direct standby

feature. The direct standby function allows two PacketShapers to work in a redundant

network topology, with each unit connected to a different router. See PacketGuide for more

information on direct standby configuration.

When compression and direct standby are both enabled, Packeteer recommends thatautomatic reprobe mode be used on PacketShapers at all branch offices. In auto reprobe

mode, the PacketShaper manages connectivity and periodically sends maintenance probes

to ensure that compressed traffic is routed via an available path. If a host does not respond

to the probe (perhaps because a router has failed, making the host unreachable through the

existing data path), the unreachable host will be removed from the compression tunnel and

the PacketShaper will attempt to re-discover it through an alternate path, if one exists.

The default probing mode is manual. To enable automatic mode, use the following CLI

command:

setup compression reprobe auto

WAN

or

Internet

Each unit’s OUTSIDE port connected to router

LAN LAN

INSIDE INSIDE

OUTSIDEOUTSIDE




Displaying Compression Reports

Viewing the

CompressionSummary

For an overview of how compression is working on your link, you can display the

Compression Summary report. The top of this report has a table that summarizescompression statistics for the Inbound and Outbound links. The Inbound statistics represent

inbound traffic that gets decompressed by the PacketShaper, and the Outbound statistics

represent outbound traffic that the PacketShaper compresses.

This report contains a total of eight graphs — four graphs for the Inbound direction and four

for Outbound. The graphs compare bandwidth usage, with and without compression, so

that you can quickly see the amount of compression on your link.

To see a meaningful Compression Summary, wait approximately an hour after enabling

compression before viewing the report.

To display the compression summary:

1. Click the report tab.

2. Click compression summary. The Compression Summary report displays in thecurrent window.

✍ Note: By default, only compressible traffic is included in the graphs and data. If you

want to show all traffic (compressible and non-compressible), select the include

non-compressible traffic in graphs and data checkbox. When this checkbox is

selected, you may also want to select the include link size in graphs checkbox.

(Link size is less meaningful when viewing only some of the traffic, as is the case

when non-compressible traffic is not included.)

3. Adjust the time period and end date, if desired.

The top of the Compression Summary report has a table that summarizes compression

statistics for the Inbound and Outbound links. Each statistic is described below:

Statistic Description

Precompression Bytes Outbound: For compressible outbound traffic, the

number of bytes before compression has been applied

Inbound: For inbound compressed traffic, the number of

bytes after decompression

Postcompression Bytes Outbound: For outbound traffic sent through a

compression tunnel, the number of bytes after

compression has been applied

Inbound: For inbound compressed traffic, the number of bytes before decompression

Bytes Saved The number of bytes that didn’t have to traverse the link,

due to compression; allows you to see how many bytes

the compression feature actually saved on the link.

Bytes Saved is the difference between precompression

bytes and postcompression bytes.




Here’s an example of one of the compression graphs in the Compression Summary.

The Compression Summary report contains the following graphs:

% Bytes Saved For traffic sent through a compression tunnel, the

percentage of bytes saved, due to compression

Bandwidth Multiple For traffic sent through a compression tunnel, the

percentage by which virtual bandwidth is increased due

to compression

Graph Description

Average Rates Compares average bandwidth usage of compressible

traffic, with and without compression. The Tunneled

Postcompression Average Rate line represents usage

with compression enabled, and the Tunneled Precompression Average Rate line represents what

average usage would have been without compression.

If you enable the include non-compressible traffic in

graphs and data checkbox, the graph includes all

traffic (compressed and non-compressible) and

compares Postcompression Average Rate with

Precompression Average Rate.

Peak Rates Compares peak bandwidth usage of compressible

traffic, with and without compression. The Tunneled

Postcompression Peak Rate line represents usage with

compression enabled and the Tunneled PrecompressionPeak Rate line represents what peak usage would have

been without compression.



traffic (compressed and non-compressible) and

compares Postcompression Peak Rate with

Precompression Peak Rate.

Statistic Description




If your Compression Summary doesn’t show any compression data, see “Problems?” on

page 10.

Compression Shows the total number of bytes recorded on the link,

with and without compression.

• The Tunneled Postcompression Bytes line shows the

number of bytes that went through a compression

tunnel.

• The Tunneled Precompression Bytes line represents

the number of bytes that would have passed through

the link if compression weren’t enabled.

• The Bytes Saved line shows the number of bytes that

didn’t have to traverse the link, due to compression;

it’s the difference between precompression and

postcompression bytes.


graphs and data checkbox, the graph includes alltraffic (compressed and non-compressible) and

compares Postcompression Bytes with Precompression

Bytes. This graph includes an additional line, Non-

compressible Bytes, which shows the number of bytes

that PacketShaper did not attempt to compress, either

because they didn’t belong to a compressible service or

because they were destined for a location without a

compression partner.

Percent Bytes Saved Shows the percentage of bytes saved on the link, due to

compression. The Tunneled Percent Bytes Saved value

is calculated by subtracting tunneled postcompression

bytes (the size after compression) from tunneledprecompression bytes (the size without any

compression) and dividing this difference by tunneled

precompression bytes. For example, if a link would

have had 700k without compression and is 400k after

being compressed, the Tunneled Percent Bytes Saved

would be approximately 43%: (700-400)/700.



traffic on the link (compressible and non-compressible).

The Percent Bytes Saved value is calculated by

subtracting precompression bytes (the size without any

compression) and postcompression bytes (the size after

compression) and dividing this difference by

precompression bytes. For example, if the link in the

example above had 100k of non-compressible traffic,

the Percent Bytes Saved would be 38%: ((700+100)-

(400+100))/(700+100).

Graph Description




Viewing the Top Ten

Compressed

Applications

PacketWise offers two reports that list the applications, services, or protocols that achieved

the most compression. A third compression-related report lists the classes that had the most

traffic along with their compression savings.

✍Note: The top ten tab is not available on the PacketShaper 1200.

To view the Top Ten compression reports:

1. Click the top ten tab on the navigation bar.

2. In the View top field, enter the number of classes you want to view in the report

(default is 10). To view all classes, clear this field so that it’s blank.

3. Click the View drop-down list and select Compression % Bytes Saved.

This report lists the classes with the highest percentage of bytes saved, due to compression,

in the designated time interval. The Compression % Bytes Saved value is calculated by

subtracting pre-compression bytes (the size without any compression) and post-

compression bytes (the size after compressible bytes were compressed) and dividing this

difference by pre-compression bytes.

4. To choose a different time interval, enter the number of minutes, hours, days, weeks,

or months in the Show field, and then select the unit of time.

For example, by entering 3 in the Show field and selecting day for the unit of time, you

create a report with the data collected over the last three days.

5. Click update to apply the new time interval settings. The new report appears.

6. To see another Top Ten compression report, click the View drop-down list and select

Compression Bytes Saved.




This report lists the classes in which compression offered the most bytes savings. For

each class, this view lists the number of bytes that didn’t have to traverse the link,

because compression was used.

7. View the Average Rate, Precompressed with % Bytes Saved report.

This report lists the classes that had the highest volume of precompressed traffic alongwith the compression savings.

If your Top Ten reports don’t show any compression data, see “Problems?” on page 10.

Problems? If your compression reports don’t show any results, check the table below for possible

problems and solutions.

Problem Solution

Cables are connected backwards. Refer to the Quick Start Guide for instructions

on connecting your PacketShaper to the

network. If you discover that you havemiscabled the unit, reconnect the cables

properly, and then turn compression off and

back on.

You are not sending/receiving flows

to/from a host on the other side of a

compression-enabled PacketShaper.

If the host does not have a compression-

enabled PacketShaper in front of it, data cannot

be compressed.

Compression is not enabled on the

partner unit(s).

PacketShaper can’t create a compression

tunnel unless the partner unit has also turned on

compression. Log in to each of the partner

units and go to the Setup tab and make sure

Compression is set to on.

Xpress-IP settings are not configured. PacketShaper will not create compression

tunnels or compress data for devices (main or

LEM) that are not configured with Xpress-IP

settings. To configure Xpress-IP settings for

each device, go to the setup tab and choose the

Compression page.




If you are still experiencing problems with compression after trying the above solutions,

use the setup compression show command in the command-line interface. This command

provides compression tunnel partner status. PacketGuide provides additional

troubleshooting details — just search for compression troubleshooting.

The Compression Summary shows

little compression savings.

Enable the checkbox include non-

compressible traffic in graphs and data and

click update. Look at the Non-compressible Bytes line in the Compression graph. If this line

shows that non-compressible bytes are at about

the same level as precompression bytes, most

of the traffic on your link is not compressible.

This could be because:

the traffic is destined to sites without

compression modules. Make a site-based

traffic tree, creating classes for each of your

branch offices. Look at compression reports

for each class. If no traffic is being compressed

to a site, it’s possible that there is no

PacketShaper, compression is not turned on, orXpress-IP settings haven’t been configured.

or

the applications are non-compressible. Go to

the Top Ten page and make note of the top

Outbound classes. Examples of non-

compressible applications are streaming media

and encrypted data. View Class Compression

Bytes Transferred graphs for each class and

enable the checkbox Include Non-

Compressible Traffic in Compression

Graphs. If the Non-compressible Bytesline is

at about the same level as the Precompression Bytes line, most of the traffic in the class is not

compressible.

You applied a never-admit policy to

the RSVP class.

The compression tunnel discovery process will

not function if the RSVP class has a never-

admit policy. Delete the policy.

Problem Solution

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