46-9
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter46 Configuring Inspection for Management Application Protocols
RADIUS Accounting Inspection
hostname# show service-policy inspect gtp statistics gsn 9.9.9.9
1 in use, 1 most used, timeout 0:00:00
GTP GSN Statistics for 9.9.9.9, Idle 0:00:00, restart counter 0
Tunnels Active 0Tunnels Created 0
Tunnels Destroyed 0
Total Messages Received 2
Signaling Messages Data Messages
total received 2 0
dropped 0 0
forwarded 2 0
Use the show service-policy inspect gtp pdp-context command to display PDP context-related
information. The following is sample output from the show service-policy inspect gtp pdp-context
command:
hostname# show service-policy inspect gtp pdp-context detail
1 in use, 1 most used, timeout 0:00:00
Version TID MS Addr SGSN Addr Idle APN
v1 1234567890123425 10.0.1.1 10.0.0.2 0:00:13 gprs.cisco.com
user_name (IMSI): 214365870921435 MS address: 1.1.1.1
primary pdp: Y nsapi: 2
sgsn_addr_signal: 10.0.0.2 sgsn_addr_data: 10.0.0.2
ggsn_addr_signal: 10.1.1.1 ggsn_addr_data: 10.1.1.1
sgsn control teid: 0x000001d1 sgsn data teid: 0x000001d3
ggsn control teid: 0x6306ffa0 ggsn data teid: 0x6305f9fc
seq_tpdu_up: 0 seq_tpdu_down: 0
signal_sequence: 0
upstream_signal_flow: 0 upstream_data_flow: 0
downstream_signal_flow: 0 downstream_data_flow: 0
RAupdate_flow: 0
The PDP context is identified by the tunnel ID, which is a combination of the values for IMSI and
NSAPI. A GTP tunnel is defined by two associated PDP contexts in different GSN nodes and is
identified with a Tunnel ID. A GTP tunnel is necessary to forward packets between an external packet
data network and a MS user.
You can use the vertical bar (|) to filter the display, as in the following example:
hostname# show service-policy gtp statistics | grep gsn
RADIUS Accounting Inspection
This section describes the IM inspection engine. This section includes the following topics:
•RADIUS Accounting Inspection Overview, page 46-9
•Configuring a RADIUS Inspection Policy Map for Additional Inspection Control, page46-10

RADIUS Accounting Inspection Overview

One of the well known problems is the over-billing attack in GPRS networks. The over-billing attack
can cause consumers anger and frustration by being billed for services that they have not used. In this
case, a malicious attacker sets up a connection to a server and obtains an IP address from the SGSN.
When the attacker ends the call, the malicious server will still send packets to it, which gets dropped by