Beta Draft Confidential
About ATM Logical Ports
ATM UNI Concepts
ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000 1/19/052-3
ATM UNI DCE and DTE
This section describes some of the concepts you need to know when defining ATM 
UNI DCE and ATM UNI DTE logical ports for CBX 3500, CBX 500, and GX 550 
switches. You can configure a single ATM UNI logical port on a physical port to 
support the following standard protocol functions:
• ATM UNI 3.0, 3.1, and 4.0 (see “ATM UNI 4.0 Support” on page 2-4 for more 
information)
• International Telecommunications Union (ITU) UNI 
• Interim Inter-switch Signaling Protocol (IISP) 3.0 and 3.1 
You use the ATM UNI DCE logical port type to communicate with most ATM CPE. 
An ATM UNI DCE logical port represents the “network side” equipment. This logical 
port supports all types of PVCs as well as SVCs. For SVC applications, the ATM UNI 
DCE logical port assumes the role of the network side of the UNI signaling interface.
You can also use the ATM UNI DCE as a feeder port for Lucent OPTimum trunks or 
virtual UNIs. When used as a feeder port, you can still use the ATM UNI DCE logical 
port for PVC and SVC applications.
The ATM UNI DTE logical port type has the identical functionality of the ATM UNI 
DCE logical port with one exception. For SVC applications, the ATM UNI DTE 
assumes the role of the “user side” of the UNI signaling interface.