Cisco ASR 5x00 Packet Data Network Gateway Administration Guide ▄
245
Appendix B
Direct Tunnel
This chapter briefly describes the 3G/4G UMTS direct tunnel (DT) feature, indicates how it is implemented on various
systems on a per call basis, and provides feature configuration procedures.
Products supporting direct tunnel include:
3G devices (per 3GPP TS 23.919 v8.0.0):
the Serving GPRS Support Node (SGSN)
the Gateway GPRS Support Node (GGSN)
LTE devices (per 3GPP TS 23.401 v8.3.0):
Serving Gateway (S-GW)
PDN Gateway (P-GW)
Important:
Direct tunnel is a licensed Cisco feature. A separate feature license is required for configuration.
Contact your Cisco account representative for detailed information on specific licensing requirements. For information
on installing and verifying licenses, refer to the
Managing License Keys
section of the
Software Management
Operations
chapter in the
System Administration Guide
.
The SGSN determines if setup of a direct tunnel is allowed or disallowed. Currently, the SGSN and S-GW are the only
products that provide configuration commands for this feature. All other products that support direct tunnel do so by
default.
This chapter provides the following information:
Direct Tunnel Feature Overview
Direct Tunnel Configuration