ITU-T - International Telecommunication Union/ITU Telcommunication Sector
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ITU-T X.86-2001
Scope
This Recommendation specifies a protocol suite structure of Ethernet frame (defined by IEEE WG 802.3) over LAPS for the purpose of providing the future protocol compatibility among peer systems in the light of ITU-T X.200@ and applies to Synchronous Digital Hierarchy (ITU-T G.707/Y.1322). LAPS protocol and specification introduced in ITU-T X.85/Y.1321 continue to be used to address its capabilities of providing the adaptation from Ethernet to LAPS. LAPS describes an HDLC-like framing structure to encapsulate IEEE 802.3 Ethernet MAC frame as shown in Figure 7@ provide a point-to-point full-duplex simultaneous bidirectional operation. Connecting Ethernet Switches to a SDH network is a very attractive way to provide Ethernet over a Wide Area Network. It is transparent to the Ethernet switch that one or more Ethernet switch ports are connected. The relationship between LAPS and Ethernet and SDH physical layer@ together with the Rate. This Recommendation does not specify the method of mapping LAPS to SDH. No change is made for all Ethernet-based protocols (including IEEE 802.3 Ethernet) and all SDH standards. NOTE 1 ?C It is intended that Ethernet over LAPS can be extended@ in future amendments@ to support additional new types of data service. NOTE 2 ?C LAPS used in this Recommendation is not used to coexist with HDLC (ISO/IEC 3309 or RFC 1662)@ LAPB/ITU-T X.25@ LAPD/ITU-T Q.921 and LAPF/ITU-T Q.922 within the same physical layer in future. NOTE 3 ?C This Recommendation shall be applied to SDH sub-rates for IEEE 802.3 Ethernet.