# Predefined Services

Services are types of IP traffic for which protocol standards exist. Each service has a port number associated with it, where the access policy accepts a request for that service.

When you create an access policy, you must define a service for it. You can select one of the pre-defined services from the Service Book, or select a custom service that you have created (see Service Configuration). Each access policy can reference either a single service, or a service group that you create from pre-defined and/or custom services (see Service Group Configuration).

### Viewing Pre-Defined Services

Name: Indicates the name of the pre-defined service.

Type: Each service displays as an icon that represents a classification of service: Remote, E-mail, Info Seeking, Security, or Other. Moving the mouse over any service listing will reveal its definition and standard TCP or UDP port assignment.

##### ICON | ##### NAME | ##### MEANING
| Remote | Various remote connection utilities such as FTP, RLOGIN, and TELNET.
| E-mail | E-mail services such as POP3 and Mail.
| Info Seeking | Information search engines such as HTTP, GOPHER, and DNS.
| Security | Security services such as SHTTP.
| Other | Miscellaneous utilities such as ICMP, SNMP, TCP-ANY, and SYSLOG.

Comment: Description of the service.

Configure: Click Edit to modify the entry.

### To Modify a Pre-Defined Service

1. In the Configure column, click Edit for the group you want to modify.

The Predefined Services Edit page appears.

2. Select one of the options for Service Timeout, and then click OK to save your changes.

Note: For more information on the H.323 and SIP protocols as well as ICMP services, refer to the NetScreen Concepts & Examples ScreenOS Reference Guide available on the documentation CD that shipped with your NetScreen product and also on the Juniper Networks support site.