Blue Coat Systems Blue Coat Systems SG Appliance Filtering the Display, About the Byte Totals

Chapter 5: Statistics

About the Byte Totals

The client and server byte total is the sum of all bytes going to and from the client or server. All application-level bytes are counted, including application overhead such as HTTP headers, CIFS headers, and so on. TCP and IP headers, packet retransmissions, and duplicate packets are not counted.

The following sections describe some of the factors that can affect the byte totals.

ADN Tunnels

If the traffic is flowing through an ADN tunnel, the bytes are counted after ADN optimization, meaning that compressed byte counts are displayed.

Multiple Server Connections

A single client connection can use many server connections. The server byte counts include the total bytes transferred over all server connections accessed over the lifetime of a client connection. Even though a server connection can serve many clients, the same server byte is never included in more than one client connection total.

Aborted Downloads

In some cases, you might see the server bytes increasing even after the client has closed the connection. This can occur when a client requests a large object and aborts the download before receiving the entire object. The server bytes continue to increase because the SG appliance is retrieving the object for caching.

Explicit Proxying and Pipelining

If clients are explicitly proxied and the session has multiple connections or is pipelined, no client bytes are displayed and the expanded server connections display no gain when the tree view is shown. This is because the SG appliance is downloading the content before serving it to the client.

What Is Not Displayed

The Proxied Sessions page does not display statistics for:

❐IM (Yahoo, AOL, MSN), DNS, SOCKS, and Telnet

❐Inbound ADN connections

❐Bridged connections

❐Administrative connections (Management Console, SSH console, SNMP, DSAT, access-logging, Director, and so on)

❐Off-box processing connections (ICAP, DRTR, etc.)

Note: In some cases, an administrative or off-box connection might correspond to a specific client connection, for example, an ICAP AV scanning connection associated with a specific HTTP client connection. However, the byte counts collected from administrative or off-box connections are not included in the Active Sessions display.

Filtering the Display

Use the Filter drop-down list to filter the proxied session statistics.

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