HDLC


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HDLC

(communications)

HDLC

HDLC

(High-level Data Link Control) A data link protocol from ISO for point-to-point communications over serial links. Derived from IBM's SDLC protocol, HDLC has been the basis for numerous protocols including X.25, ISDN, T1, SS7, GSM, CDPD, PPP and others. Various subsets of HDLC have been developed under the name of Link Access Procedure (LAP).

In HDLC, one side is set up as the primary control station and the other as secondary. In Normal mode, the secondary station responds to requests only from the primary station. In Asynchronous mode, the secondary can initiate transmission, and in Asynchronous Balanced mode, both sides can send and receive over full-duplex lines. See LAP and SDLC.
References in periodicals archive ?
The ensuing hyperinsulinaemia is associated with increased serum free fatty acid levels, raised triglycerides, moderately raised LDLC, and decreased HDLC.
To simulate the analytical variations about a set of preselected values for TC, HDLC, and hsCRP, Monte Carlo simulation software was written in Visual Basic for Applications within Microsoft Excel.
Designers can integrate Triscend's HDLC core in seconds via drag-and-drop within Triscend's FastChip software.
designs PCI bridges, PCI mastering high speed HDLC controllers for high speed communications and provides a family of companion PCI solutions for the telecommunications system, video conferencing system and server systems with PCI bus backbones.
Hybrid mode detects TDM diagnostic loop codes in the T1 or E1 circuit and automatically changes the mode of operation to transmit full DS0 bit streams encapsulated in IP/Ethernet or to revert to HDLC encapsulation.
Densitometric scanning of electrophoretograms (HYRYS densitometer 1012; SEBIA) at 540 nm, using a green filter (or at 420 nm, using a blue filter), allowed quantification of colorimetric intensities of bands corresponding to LDLC, of an intermediate band corresponding to VLDL-cholesterol (VLDLC) and lipoprotein(a) [Lp(a)], and of a band corresponding to HDLC (Fig.
With the integration of Mindspeed's HDLC products and Continuous Computing's Trillium protocol software, we are able to offer TEMs a combined solution with the same core technology, allowing for low risk, quick implementation and cost savings," said Mike Dagenais, chief executive officer of Continuous Computing.
integration of a greater number of HDLC channels on a single chip, the
Axerra's AXN Pseudo-Wire Gateways and Access Devices provide the most comprehensive set of voice and data Pseudo-Wire services in the industry: Circuit Emulation Pseudo-Wire, Frame Relay and HDLC Pseudo-Wires, ATM Pseudo-Wires, plus Ethernet and IP aggregation services while preserving security and QoS/CoS over next-generation packet-access networks.
Mindspeed's highly integrated, 1,024 multi-channel HDLC controller used in conjunction with its high-density BAM and multi-port T3/E3 LIU devices enable Huawei-3Com to develop a high-density, software configurable datacom router.
The M2931x family incorporates independent system interfaces to support cell and packet termination into an industry-standard system bus of UTOPIA Level 2 (UL2) for ATM, and POS-PHY Level 2 packets and/or SPI-3 for ATM cells, HDLC and GFP packets.