Frame Relay - for Faster and More Efficient Data Communications ...
Frame Relay - for Faster and More Efficient Data Communications ... Frame Relay - for Faster and More Efficient Data Communications ...
42Table 2Relationship between Functional and InformationModelFunctional Model,see Fig. 6Managed Objects in InformationModel, see Fig. 18TransportFunctionTrailConnectionTrail (Managed Object)Connection (Managed Object)TransportReferencePointsEnd point of trail APEnd point of a connection CPor network connection TCPTrail Termination Point TTP(Managed Object)Connection Termination Point CTP(Managed Object)Fig. 12Functional Model of PDH muldex and line systemDS1D1PHTFramed 2 Mbit/s signalHDB-3 coded 2 Mbit s signalPhysical Media TrailRelationshipsbetweenTransportReferencePointsand relatedManagedObjectsOne-to-one relationshipbetween AP and CPOne-to-one relationshipbetween CP/TCP and CPOne-to-n relationshipbetween AP in a serverlayer and CP in aclient layerOne-to-one relationshipbetween TTP and CTPexpressed by connectivitypointersOne-to-one relationshipbetween CTP and CTPexpressed by connectivity pointersOne-ton relationshipbetween I l P in a server layerand CTP in a client layerexpressed by namingClient-to-server AdaptationTrail TerminationERICSSON REVIEW No. 1-2, 1992
43layers, Table 1. Each function is characterisedby a number, which appears in tablesand figures in a consistent way. (Thesame number is used for the send and receiveparts).The example in Fig. 12 is based on the examplein Fig. 11 and shows the connectionof the terminals via a line system consistingof line terminals and one regenerator.Thirty 64 kbit/s Circuit Trails are transmittedvia a DS1 Trail which consists ofTrail Terminations, two Sub-Network Connections(TCP-CP) and one Link Connection(CP-CP) in the Path Layer network.These Sub-Network and Link Connectionsare served by three D1 Trails in the SignalLayer network. The D1 Trail in the middleconsists of Trail Terminations and two LinkConnections.The D1 Trail is served by two PhysicalTrails, i.e. two cable sections separated bya regenerator in the physical layer.Fig. 13 shows the Functional Model of adigital multiplexer converting 64x2 Mbit/ssignals into one 140 Mbit/s signal. Terminala is connected to a digital multiplexera, and the multiplexer is connected to a140 Mbit/s line terminal a. Similarly, thecorresponding b-side contains line terminalb, digital multiplexer b and terminal b.The multiplexers and line terminals containresources for management. TransportFunctions 1 to 4 are explained in Table 1and functions 10 to 19 in Table 3.Synchronous Digital Hierarchy (SDH)The functions of SDH systems, as definedin CCITT Recommendations G.781, 782and 783 for digital multiplexers and for digitalcross connects, are much more complicatedthan PDH systems that conformto existing Series G Recommendations (-Blue Book). This is compensated by the increasedflexibility and manageability ofSDH systems, however. Ample overheadinformation, the corresponding resourcesand management interfaces suitable forFig. 13Functional Model of PDH multiplexer (64x2 Mbit/sto 140 Mbit/s)ERICSSON REVIEW No. 1-2, 1992
- Page 1: ERICSSONREVIEW1-21992Frame Relay -
- Page 4 and 5: ERICSSON REVIEWBO HEDFORSPublisher
- Page 6 and 7: 4Fig. 2Distributed computer environ
- Page 8 and 9: Fig. 7A company's data network shou
- Page 10 and 11: 8Fig. 11The frame format used for F
- Page 12 and 13: 10er (DE, Fig. 12) should be set to
- Page 14 and 15: Computerised System for QualityInsp
- Page 16 and 17: Box 1Code39, the first alphanumeric
- Page 18 and 19: 16Fig. 6Cable attenuation test at E
- Page 20 and 21: 18Fig. 9Installing the Dehlfi syste
- Page 22 and 23: Human Factors - A Key to ImprovedQu
- Page 24 and 25: 221 Use the user's model2 Introduce
- Page 26 and 27: 24Fig. 5Advanced Human Factors desi
- Page 28 and 29: Fig. 7User interface for PBX attend
- Page 30 and 31: Cell-voltage EqualisersSeries BMP 1
- Page 32 and 33: 30Box1CELL-VOLTAGE EQUALISER BMP 16
- Page 34 and 35: 32age, the faulty cell or the entir
- Page 36 and 37: In Search of Managed ObjectsWalter
- Page 38 and 39: Fig. 4The telecommunication network
- Page 40 and 41: Fig. 6Functional Model illustrating
- Page 42 and 43: 40Fig. 9Combination of layering and
- Page 46 and 47: 44No1PPI2PPI3SLTTransport Function(
- Page 48 and 49: 46Table 4SDH functions, Resources a
- Page 50 and 51: The Managed Objects and their prope
- Page 52 and 53: 50Fig. 21Information Model of PDH d
- Page 54 and 55: Fig. 25Information Model of SDH mul
- Page 56 and 57: 54Table 5Cross-connect functions, R
- Page 58: Fig. 32, leftCross-connect Fragment
43layers, Table 1. Each function is characterisedby a number, which appears in tables<strong>and</strong> figures in a consistent way. (Thesame number is used <strong>for</strong> the send <strong>and</strong> receiveparts).The example in Fig. 12 is based on the examplein Fig. 11 <strong>and</strong> shows the connectionof the terminals via a line system consistingof line terminals <strong>and</strong> one regenerator.Thirty 64 kbit/s Circuit Trails are transmittedvia a DS1 Trail which consists ofTrail Terminations, two Sub-Network Connections(TCP-CP) <strong>and</strong> one Link Connection(CP-CP) in the Path Layer network.These Sub-Network <strong>and</strong> Link Connectionsare served by three D1 Trails in the SignalLayer network. The D1 Trail in the middleconsists of Trail Terminations <strong>and</strong> two LinkConnections.The D1 Trail is served by two PhysicalTrails, i.e. two cable sections separated bya regenerator in the physical layer.Fig. 13 shows the Functional Model of adigital multiplexer converting 64x2 Mbit/ssignals into one 140 Mbit/s signal. Terminala is connected to a digital multiplexera, <strong>and</strong> the multiplexer is connected to a140 Mbit/s line terminal a. Similarly, thecorresponding b-side contains line terminalb, digital multiplexer b <strong>and</strong> terminal b.The multiplexers <strong>and</strong> line terminals containresources <strong>for</strong> management. TransportFunctions 1 to 4 are explained in Table 1<strong>and</strong> functions 10 to 19 in Table 3.Synchronous Digital Hierarchy (SDH)The functions of SDH systems, as definedin CCITT Recommendations G.781, 782<strong>and</strong> 783 <strong>for</strong> digital multiplexers <strong>and</strong> <strong>for</strong> digitalcross connects, are much more complicatedthan PDH systems that con<strong>for</strong>mto existing Series G Recommendations (-Blue Book). This is compensated by the increasedflexibility <strong>and</strong> manageability ofSDH systems, however. Ample overheadin<strong>for</strong>mation, the corresponding resources<strong>and</strong> management interfaces suitable <strong>for</strong>Fig. 13Functional Model of PDH multiplexer (64x2 Mbit/sto 140 Mbit/s)ERICSSON REVIEW No. 1-2, 1992