Cisco Cisco ASR 5500 トラブルシューティングガイド
Contents
Introduction
Protocol Stack on Gb Interface
Normal Message Flow on Gb for NSEI Creation/Reset and NSVC Reset
Problem
Troubleshoot
Related Cisco Support Community Discussions
Introduction
This document describes about the Gb interface and its protocol stack in the GPRS Network
Architecture and provides a good understanding to troubleshoot the problem with Network Service
Virtual Connection (NSVC) and Network Service Entity Identifier (NSEI) in Gb over IP Network on
the Cisco Aggregated Service Router(ASR) 5x00 Series.
Architecture and provides a good understanding to troubleshoot the problem with Network Service
Virtual Connection (NSVC) and Network Service Entity Identifier (NSEI) in Gb over IP Network on
the Cisco Aggregated Service Router(ASR) 5x00 Series.
Protocol Stack on Gb Interface
The Gb interface connects the Base Station System (BSS) and the Serving GPRS Support Node
(SGSN). It allows the exchange of signaling information and user data. Base Station Controller
(BSC) and SGSN vendor can be different because it is open system interface, so it is important to
understand the message flow between the BSS and SGSN in order to identify the element in
question and rectify the issue.
(SGSN). It allows the exchange of signaling information and user data. Base Station Controller
(BSC) and SGSN vendor can be different because it is open system interface, so it is important to
understand the message flow between the BSS and SGSN in order to identify the element in
question and rectify the issue.
The Gb interface implements a protocol stack in the SGSN and the BSS that includes a User
Datagram Protocol (UDP) layer over an IP layer. Data packets are then transmitted between the
BSS and the SGSN over a connectionless IP network. The data packets carry information
between functional entities in the SGSN and functional entities in the BSS.
Datagram Protocol (UDP) layer over an IP layer. Data packets are then transmitted between the
BSS and the SGSN over a connectionless IP network. The data packets carry information
between functional entities in the SGSN and functional entities in the BSS.
The stack also includes a modified Network Services (NS) layer which is divided into an upper NS
Network Service Control (NS-NSC) sub-layer and a lower NS-SubNetwork Service (NS-SNS) sub-
layer. The NS-NSC sub-layer maps to the Base Station System GPRS Protocol (BSSGP) layer
Network Service Control (NS-NSC) sub-layer and a lower NS-SubNetwork Service (NS-SNS) sub-
layer. The NS-NSC sub-layer maps to the Base Station System GPRS Protocol (BSSGP) layer