Network Service Access Point Identifier

From Wikipedia, the free encyclopedia

This article may require cleanup to meet Wikipedia's quality standards.
Please discuss this issue on the talk page or replace this tag with a more specific message.
This article has been tagged since April 2006.

NSAPI, or Network (Layer) Service Access Point Identifier, is an identifier used in GPRS (cellular data) networks.

It is used to identify a Packet Data Protocol (PDP) context (a unique data session) in the Mobile Station (MS) and in the Serving GPRS Support Node (SGSN). It is dynamically selected by the MS (however, the MS should ensure that the selected NSAPI is not currently being used by another session management entity in the MS). When the MS requests a PDP context, it selects a NSAPI that it sends to the SGSN with the request.

NSAPI is also used as part of the Tunnel Identifier between GPRS Support Nodes (GSNs). The user identity (International Mobile Subscriber Identity (IMSI)) and the application identifier (NSAPI) are integrated into the Tunnel Identifier (GTPv0) (TID) or Tunnel Endpoint Identifier (GTPv1) (TEID) that uniquely identifies the subscriber’s sublink between the GSNs (SGSN and GGSN). The SGSN inserts the NSAPI along with the GGSN address in the "Activate PDP Context Request". One PDP context may have several (secondary) PDP contexts and NSAPI. The NSAPI is an integer value within the PDP context header.

In the UMTS system the data connection between a core network and a mobile station is identified using a NSAPI, that identifies as well a radio access bearer. In the previous releases of GPRS (pre- Release'00), a connection is identified by NSAPI and a Logical Link Control (LLC) protocol SAPI. However, in UMTS, and thus in GPRS Release'00, the LLC protocol is no longer used.

(N.B. The NSAPI acronym is also used for "Netscape Server Application Programming Interface").

Retrieved from "http://en.wikipedia.org../../../n/e/t/Network_Service_Access_Point_Identifier_9ffd.html"
Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.