Cisco Cisco ASR 5700 Guide De Dépannage
Contents
Introduction
Problem
Scenarios
Scenario 1.
Scenario 2.
Why Radio Access Bearer (RAB) Assignment Fails?
Workaround
Related Cisco Support Community Discussions
Introduction
This document describes a specific scenario where Extended Bit Rate Parameter is suppressed
by Serving GPRS Supporting Node (SGSN). This problem is reported on Cisco Aggregrated
Service Routers (ASR) 5x00.
by Serving GPRS Supporting Node (SGSN). This problem is reported on Cisco Aggregrated
Service Routers (ASR) 5x00.
Problem
The roaming subscribers are unable to establish Packet Data Protocol (PDP) context when
roaming in particular circle because SGSN rejects PDP with Cause Code field having insufficient
resources, due to which 3G roaming calls are not setup properly. Roaming Home Location
Register (HLR) sends 0 kbps values in Max Bit Rate Down Link (DL) and also adds Extended
Quality of Service(QoS) irrespective of Radio Access Type (RAT) Type. But SGSN ignores the
Extended QOS and sends Create PDP Request message to the Gateway GPRS Supporting Node
(GGSN) with 0 kbps, resulting in Radio Access Bearer(RAB) assignment failure.
roaming in particular circle because SGSN rejects PDP with Cause Code field having insufficient
resources, due to which 3G roaming calls are not setup properly. Roaming Home Location
Register (HLR) sends 0 kbps values in Max Bit Rate Down Link (DL) and also adds Extended
Quality of Service(QoS) irrespective of Radio Access Type (RAT) Type. But SGSN ignores the
Extended QOS and sends Create PDP Request message to the Gateway GPRS Supporting Node
(GGSN) with 0 kbps, resulting in Radio Access Bearer(RAB) assignment failure.
Scenarios
As per 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 24.008
Specification, its clearly stated that:
Specification, its clearly stated that:
Maximum bit rate for downlink, octet 9 (see 3GPP TS 23.107 [81])
Coding is identical to that of Maximum bit rate for uplink.
If the sending entity wants to indicate a Maximum bit rate for downlink higher than 8640 kbps, it
shall set octet 9 to "11111110", i.e. 8640 kbps, and shall encode the value for the Maximum bit
rate in octet 15.
Coding is identical to that of Maximum bit rate for uplink.
If the sending entity wants to indicate a Maximum bit rate for downlink higher than 8640 kbps, it
shall set octet 9 to "11111110", i.e. 8640 kbps, and shall encode the value for the Maximum bit
rate in octet 15.
In this version of the protocol, for messages specified in the present document, the sending entity
shall not request 0 kbps for both the Maximum bitrate for downlink and the Maximum bitrate for
uplink at the same time. Any entity receiving a request for 0 kbps in both the Maximum bitrate for
downlink and the Maximum bitrate for uplink shall consider that as a syntactical error (see clause
8).
shall not request 0 kbps for both the Maximum bitrate for downlink and the Maximum bitrate for
uplink at the same time. Any entity receiving a request for 0 kbps in both the Maximum bitrate for
downlink and the Maximum bitrate for uplink shall consider that as a syntactical error (see clause
8).
Scenario 1.