1 LAPB The LAPB module implements one of the protocols in the Link layer described by the Digital Network Architecture. You must install the product DEC WAN Device Drivers before you can refer to the LAPB Module entities in an NCL command. The lapb entity is the top-level entity in the LAPB module hierarchy of entities. The LAPB module implements the LAPB link-level protocol which is a variation of the HDLC link-level protocol. 2 character =title = Characteristic Attibutes VERSION Default: None Version: Current version number Version number of the DNA HDLC architecture to which this implementation conforms. You cannot modify this characteristic. 2 LINK =title LAPB Link A lapb link entity is associated with a port of the supporting Physical layer, and contains attributes that describe local LAPB operation. The simple-name refers to the link managed by this command. 3 character =title Charateristic Attributes ACKNOWLEDGE TIMER Default: Supplied by profile Value: 1--60000 Time, in milliseconds, to wait for an acknowledgment before initiating recovery action. This attribute corresponds to the LAPB parameter T1. You can modify this characteristic only when the entity is disabled. HOLDBACK TIMER Default: Implementation specific Value: 0--60000 Delay, in milliseconds, before an acknowledgment must be sent. This characteristic corresponds to the LAPB parameter T2. You can modify this characteristic only when the entity is disabled. INTERFACE TYPE Default: DTE Value: DCE or DTE Address mode for this link. DCE - Use DCE address mode. DTE - Use DTE address mode. You can modify this characteristic only when the entity is disabled. MAXIMUM DATA SIZE Default: Supplied by profile Value: 1--65532 Maximum frame size, in octets, of an information field in an I-frame. PHYSICAL LINE Default: No default Value: Local-entity-name Name of the Physical layer and line entity over which the LAPB protocol is to operate. You must give this characteristic a value before you enable the link. POLL TIMER Default: Implementation specific Value: Supplied by profile Maximum period in seconds that may elapse without frames being exchanged on the Data Link. On expiration, an RR(P) is sent to elicit a response from the other end. PROFILE Default: No default Value: String Name of the X.25 Level 2 Profile that defines subscription details associated with the PSDN to which this DTE is connected. You cannot modify this characteristic. This characteristic is set by means of an argument to the create command. RECEIVE BUFFERS Default: Implementation specific Value: 1--128 Specifies the number of receive data buffers. RETRY MAXIMUM Default: Supplied by profile Value: 1--255 Maximum number of times that a frame will be retransmitted before assuming a fatal error, at which point more drastic error recovery action will be attempted. This characteristic corresponds to the LAPB parameter N2. SEQUENCE MODULUS Default: Supplied by profile Value: 8 or 128 Type of sequence numbering. 8 - Use normal sequence numbering. 128 - Use extended sequence numbering. WINDOW SIZE Default: Supplied by profile Value: 1--127 Window size for transmitting and receiving I-frames. This characteristic corresponds to the LAPB parameter K. 3 counter =title Counter Attributes BUFFER UNAVAILABLE ERRORS Number of times that the underlying framing level has indicated system buffer unavailability to the Data Link layer. CRC ERRORS RECEIVED Number of frames received with a bad CRC. DATA OCTETS RECEIVED Number of data octets received from the remote station. This value does not include retransmissions. DATA OCTETS SENT Number of data octets sent to the remote station. This value does not include retransmissions. DATA PDUS RECEIVED Number of I-frames received from the remote station. This value does not include retransmissions. DATA PDUS SENT Number of I-frames sent to the remote station. This value does not include retransmissions. FRMRS RECEIVED Number of FRMR frames received. FRMRS SENT Number of FRMR frames generated as a result of invalid incoming frames. POLLS RECEIVED Number of command frames received with the P-bit set. REJS RECEIVED Number of REJ frames received. REJS SENT Number of REJ frames transmitted. RNRS RECEIVED Number of RNR frames received. RNRS SENT Number of RNR frames transmitted. TIMES ACKNOWLEDGE TIMER EXPIRED Number of times the local acknowledge timer has expired. TIMES LINK HALTED Number of times the link halt event has been generated. TIMES LINK INITIALIZING Number of times the link initializing event has been generated. TIMES LINK INOPERATIVE Number of times the link inoperative event has been generated. TIMES LINK MAINTENANCE Number of times the link maintenance event has been generated. TIMES LINK RESETTING Number of times the link reset event has been generated. TIMES LINK RUNNING Number of times the link running event has been generated. TIMES LINK SETUP FAILED Number of times the link setup failure event has been generated. TIMES LINK STATE CHANGED Number of times a link state transition has occurred. TIMES PDU RECEIVE OVERRUN Number of times a physical line indicated an overrun condition to the Data Link layer. TIMES PDU TRANSMIT FAILED Number of times an attempt to transmit a frame has failed. 3 status =title Status Attributes LINE TYPE Type of line over which this link operates. NONSWITCHED - The line is a nonswitched line. SWITCHED - The line is a switched line. MAXIMUM PDU SIZE Maximum frame size, in octets, that this station will receive and transmit. This value includes the frame header. PHYSICAL PORT Name of the Physical layer port with which the link is associated. PROTOCOL STATE State of the LAPB protocol with respect to the remote station. ERROR - The protocol is in a recognized error state. HALTED - The protocol has halted. INITIALIZING - The protocol is being initialized. INOPERATIVE - The protocol cannot be started without connectivity to the remote station. MAINTENANCE - The link is in maintenance mode. RESETTING - The protocol is undergoing a reset operation. RUNNING - The protocol is running normally. STATE Status of the lapb link entity. OFF - The link is disabled. ON - The link is enabled. 2 port =title Lapb Port A lapb port entity represents an access point for LAPB module clients to Data Link layer services. The port-name refers to the port managed by this command. 3 status =title Status Attributes CLIENT NAME Name of the client with which the port is associated. LINK Name of the link with which the port is associated. STATE State of the lapb port entity. OPEN - The port is assigned to a client. OPEN DISABLED - The port is assigned to a client, but the associated link is disabled. TYPE Type of port. SEQUENCED - The port is used for sending LAPB data. UNSEQUENCED - The port is used for sending loopback data. This is only possible if the maintenance mode characteristic of the relevant lapb link entity is set to true.