WCCP service group definition guidelines

WCCP service groups control communication

Communication between WCCP routers, appliances, and third-party proxy-cache servers is controlled by the WCCP service group to which the device belongs. Service groups comprise one or more proxy-cache servers and one or more WCCP routers. Service groups specify the type (or types) of traffic the router should redirect and the identity of all target proxy-cache servers.

About WCCP quick fill templates

Most basic service group definition tasks can be accomplished using the quick fill templates provided in the Appliance Manager and CLI. Quick fill templates provide service group details for the default traffic settings configured on the appliance. (These default settings correspond to the RFC-specified port settings for the specified traffic.) The quick fill templates should meet most of your service group requirements. You can alter entries provided by NetCache as necessary.

The Quick Fill Templates option is located on the New WCCP Service Group page. To access the New WCCP Service Group page, select Setup tab > Transparency > WCCP Service Groups, and then click New Group.

Note
IP spoofing requires additional service group configuration. See IP spoofing deployment requirements for WCCP for more information about IP spoofing for WCCP.

Service group definition guidelines

The following table provides a brief summary of service group definition guidelines.

Recommendation	Reason
Attempt to define service groups using a quick fill template first.	The quick fill templates automatically provide defaults for most of the required service group information.
Define and enable the same service group on all proxy-cache servers and routers that you want to include in the service group.	Proxy-cache servers and routers that do not have a particular service group defined and enabled will not receive or redirect the specified traffic.
Assign a unique ID to each service group.	Different service groups cannot share the same ID. You can use any number between 0 and 255, but the number cannot already be assigned to another service group. This service group ID restriction applies only to enabled service groups.
Enable the protocol and associated ports for the traffic you are redirecting before defining a service group.	Disabled protocols and ports cannot be listed in a service group.
List client-side and server-side port numbers in separate service groups.	Client-side and server-side port numbers cannot be listed in the same service group.
List each type of port traffic in only one service group.	A specific type of port traffic must be handled by only one service group. For example, you cannot create one service group to handle HTTP TCP port 80 and another service group to handle HTTP TCP port 80 and TCP port 8080.
Create no more than eight service groups.	Currently, a WCCP router can be configured for only eight service groups. If you need to redirect more than eight types of traffic, you must list multiple services in a service group. Services that use the same transport protocols can be listed in the same service group.
Set a WCCP service group password.	The WCCP service group password restricts unauthorized users from joining a WCCP service group.
Define a client-side and a server-side service group if you are implementing IP spoofing.	For IP spoofing, you must define both client-side and server-side service groups so that server responses will be directed back to the appliances. For more information, see IP spoofing deployment requirements for WCCP.
Define and enable two client-side service groups for Apple QuickTime streaming: one for the control connection and one for the feedback connection. Network Appliance recommends that you enable two service groups for the control and feedback connections for all streaming media, including RealNetworks and Windows Media.	Apple QuickTime streaming requires the UDP feedback channel.

Defining service groups for streaming media

When streaming media is delivered to clients, separate connections typically exist for the control and feedback information. Although you can force streaming clients to use the control connection (TCP) only, you must allow both the control and feedback connections to ensure optimum streaming media quality. (Apple QuickTime streaming requires both the control and feedback channels.)

To redirect the streaming media control and feedback channels, you must define one service group for the control connection and another service group for the feedback connection.

MMS

For MMS streaming traffic, use the Dynamic Client MMS Control and Dynamic Client MMS Feedback quick fill templates to create the control and feedback service groups.

RTSP

For RTSP streaming traffic, use the Dynamic Client RTSP Control and Dynamic Client RTSP Feedback quick fill templates to create the control and feedback service groups.