IDU (Interface Data Unit)

In asynchronous transfer mode (ATM), referring to a frame of data pre-

sented to an ATM interface for switching. ATM Adaptation Layer 3/4 (AAL3/4) supports message mode service, in which only one IDU is passed. AAL3/4 also supports streaming mode service, in which multiple interface data units (IDUs) are passed in a data stream. An IDU can be up to 65,535 octets in length, with a cyclic redundancy check (CRC) added as part of the trailer. See also AAL3/4, ATM, CRC, frame, IDU, message mode service, octet, streaming mode service, and trailer.

• operations and maintenance (O&M)
• operations support system (OSS)
• operator
• operator
• operator
• OPS (Off-Premises Station)
• optical
• optical add/drop multiplexer (OADM)
• Optical Carrier (OC)
• optical character recognition (OCR)
• optical cross-connect (OXC)
• optical data unit (ODU)
• optical-electrical-optical (OEO)
• optical fiber
• optical fiber, conductive (OFC)
• optical fiber, conductive, plenum (OFCP)
• optical fiber, conductive, riser (OFCR)
• optical fiber, nonconductive (OFN)
• optical fiber, nonconductive, plenum (OFNP)
• optical fiber, nonconductive, riser (OFNR)
• optical isolator
• optical line-of-sight (optical LOS)
• optical line terminal (OLT)
• optical mark recognition (OMR)
• optical network terminal (ONT)