Network service access point address
This article provides insufficient context for those unfamiliar with the subject.(October 2009) |
A network service access point address (NSAP address), defined in ISO/IEC 8348, is an identifying label for a
These are roughly comparable to
Allocation and scope
NSAP addresses are allocated by the International Organization for Standardization (ISO), through a system of delegated authorities, which are generally national standards organizations. One of the schemes to generate NSAPs uses E.164 which is the addressing format describing telephone numbers.
NSAP addresses do not specify where a network terminal is located.
NSAP addresses are used in the following OSI-based network technologies:
- ATM switched virtual circuit networks
- X.25 (see ITU-T X.121 for addressing in public data networks)
- Frame Relay
- IS-IS
- Synchronous Optical Networkingnetworks.
NSAP-style addresses are used in the IS-IS routing protocol.
Network selector
The network selector (NSEL) is a field in the NSAP address that identifies the network layer service to which a packet should be sent. This part of the address for a router will always be 0x00. In the IS-IS routing protocol, the field is sometimes referred to as the SEL field.[1][2]