Direct Tunnel
▀ Direct Tunnel Configuration
▄ Cisco ASR 5x00 Packet Data Network Gateway Administration Guide
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Direct Tunnel Configuration
The following configurations are provided in this section:
Configuring Direct Tunnel Support on the SGSN
Configuring S12 Direct Tunnel Support on the S-GW
The SGSN/S-GW direct tunnel functionality is enabled within an operator policy configuration. One aspect of an
operator policy is to allow or disallow the setup of direct GTP-U tunnels. If no operator policies are configured, the
system looks at the settings in the system operator policy named
default
.
By default, direct tunnel support is
disallowed
on the SGSN/S-GW
allowed
on the GGSN/P-GW.
Important:
If direct tunnel is allowed in the
default
operator policy, then any incoming call that does not have
an applicable operator policy configured will have direct tunnel
allowed
.
For more information about operator policies and configuration details, refer to
Operator Policy
.
Configuring Direct Tunnel Support on the SGSN
The following is a high-level view of the steps, and the associated configuration examples, to configure the SGSN to
setup a direct tunnel.
Before beginning any of the following procedures, you must have completed (1) the basic service configuration for the
SGSN, as described in the
Cisco ASR Serving GPRS Support Node Administration Guide
, and (2) the creation and
configuration of a valid operator policy, as described in the
Operator Policy
chapter in this guide.
Step 1
Configure the SGSN to setup GTP-U direct tunnel between an RNC and an access gateway by applying the example
configuration presented in the
Enabling Setup of GTP-U Direct Tunnels
section below.
Step 2
Configure the SGSN to allow GTP-U direct tunnels to an access gateway, for a call filtered on the basis of the APN, by
applying the example configuration presented in the
Enabling Direct Tunnel per APN
section below.
Important:
It is only necessary to complete either step 2 or step 3 as a direct tunnel can not be setup
on the basis of call filtering matched with both an APN profile and an IIMEI profile.
Step 3
Configure the SGSN to allow GTP-U direct tunnels to a GGSN, for a call filtered on the basis of the IMEI, by applying
the example configuration presented in the
Enabling Direct Tunnel per IMEI
section below.
Step 4
Configure the SGSN to allow GTP-U direct tunnel setup from a specific RNC by applying the example configuration
presented in the
Enabling Direct Tunnel to Specific RNCs
section below.
Step 5
(Optional)
Configure the SGSN to disallow direct tunnel setup to a single GGSN that has been configured to allow it in
the APN profile. This command allows the operator to restrict use of a GGSN for any reason, such as load balancing.
Refer to the
direct-tunnel-disabled-ggsn
command in the
SGTP Service Configuration Mode
chapter of the
Command Line Interface Reference
.
