CSMNCD
`
`27.1.2.2.1 Internal segment compatibility
`
`IEEE
`Std 802.3u-1995
`
`Implementations of the repeater set that contain a MAC layer for network management or other purposes,
`irrespective of whether they are connected through an exposed repeater port or are internally ported, shall
`conform to the requirements of clause 30 on that port if repeater management is implemented.
`
`27.1.3 Relationship to PHY
`
`A close relationship exists between clause 27 and the PHY clauses, clause 23 for the 100BASE-T4 PHY and
`clauses 24 to 26 for the IOOBASE-X PHYs. The PHY’s PMA, PCS, and MDI specification provide the
`actual medium attachment, including drivers, receivers, and Medium Interface Connectors for the various
`supported media. The repeater clause does not define a new PHY; it utilizes the existing PHYS complete and
`without modification.
`
`27.2 PMA interface messages
`
`The messages between the repeater unit and the PMA in the PHY utilizes the PMA service interface defined
`in 23.3 and 24.3. The PMA service interface primitives are summarized below:
`
`PMA_TYPE.indicate
`
`PMA_UNITDATA.request
`
`PMA_UNITDATA.indicate
`
`PMA_CARRIER.indicate
`
`PMA_LINK.indicate
`
`PMA_RXERROR.indicate
`
`27.3 Repeater functional specifications
`
`A repeater set provides the means whereby data from any segment can be received under worst case noise,
`timing, and amplitude conditions and then retransmitted with timing and amplitude restored to all other
`attached segments. Retransmission of data occurs simultaneously with reception. If a collision occurs, the
`repeater set propagates the collision event throughout the network by transmitting a Jam signal. If an error is
`received by the repeater set, no attempt is made to correct it and it is propagated throughout the network by
`transmitting an invalid signal.
`
`The repeater set provides the following functional capability to handle data flow between ports:
`
`a)
`
`b)
`
`Signal restoration. Provides the ability to restore the timing and amplitude of the received signal
`prior to retransmission.
`Transmitfimction. Provides the ability to output signals on the appropriate port and encoded appro-
`priately for that port. Details of signal processing are described in the specifications for the PHYS.
`Receivefimcrion. Provides the ability to receive input signals presented to the ports. Details of signal
`processing are described in the specifications for the PHYS.
`d) Data-Handlingfunction. Provides the ability to transfer code—elements between ports in the absence
`of a collision.
`
`c)
`
`e)
`
`f)
`
`g)
`
`Received Event-Handling requirement. Provides the ability to derive a carrier signal from the input
`signals presented to the ports.
`Collision-Handlingfimction. Provides the ability to detect the simultaneous reception of frames at
`two or more ports and then to propagate a Jam message to all connected ports.
`Error-Handlingfunction. Provides the ability to prevent substandard links from generating streams
`of false carrier and interfering with other links.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this stang@_;,rd.
`
`
`
`Aerohive - Exhibit 1025
`0224
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`h)
`
`i)
`
`Partition function. Provides the ability to prevent a malfunctioning port from generating an exces-
`sive number of consecutive collisions and indefinitely disrupting data transmission on the network.
`Receive Jabberfimction. Provides the ability to interrupt the reception of abnormally long streams
`of input data.
`
`27.3.1 Repeater functions
`
`The repeater set shall provide the Signal Restoration, Transmit, Receive, Data Handling, Received Event
`Handling, Collision Handling, Error Handling, Partition, and Receive Jabber functions. The repeater is trans-
`parent to all network acquisition activity and to all DTEs. The repeater will not alter the basic fairness crite-
`rion for all DTEs to access the network or weigh it toward any DTE or group of DTEs regardless of network
`location.
`
`The Transmit and Receive functional requirements are specified by the PHY clauses, clause 23 for
`l0OBASE-T4 and clauses 24 to 26 for l00BASE-X.
`
`27.3.1.1 Signal restoration functional requirements
`
`27.3.1.1.1 Signal amplification
`
`The repeater set (including its integral PHYS) shall ensure that the amplitude characteristics of the signals at
`the MDI outputs of the repeater set are within the tolerances of the specification for the appropriate PHY
`type. Therefore, any loss of signal—to—noise ratio due to cable loss and noise pickup is regained at the output
`of the repeater set as long as the incoming data is within system specification.
`
`27.3.1.1.2 Signal wave-shape restoration
`
`The repeater set (including its integral PHYs) shall ensure that the wave-shape characteristics of the signals
`at the MDI outputs of a repeater set are within the specified tolerance for the appropriate PHY type. There-
`fore, any loss of wave-shape due to PHYS and media distortion is restored at the output of the repeater set.
`
`27.3.1.1.3 Signal retiming
`
`The repeater set (including its integral PHYS) shall ensure that the timing of the encoded data output at the
`MDI outputs of a repeater set are within the specified tolerance for the appropriate PHY type. Therefore, any
`receive jitter from the media is removed at the output of the repeater set.
`
`27.3.1.2 Data-handling functional requirements
`
`27.3.1.2.1 Data frame forwarding
`
`The repeater set shall ensure that the data frame received on a single input port is distributed to all other out-
`put ports in a manner appropriate for the PHY type of that port. The data frame is that portion of the packet
`afier the SFD and before the end-of-frame delimiter. The only exceptions to this rule are when contention
`exists among any of the ports, when the receive port is partitioned as defined in 27.3.1.6, when the receive
`port is in the Jabber state as defined in 27.3.1.7, or when the receive port is in the Link Unstable state as
`defined in 27.3.l.5.1. Between unpartitioned ports, the rules for collision handling (see 27.3.1.4) take prece-
`dence.
`
`27.3.1.2.2 Received code violations
`
`The repeater set shall ensure that any code violations received while forwarding a packet are propagated to
`all outgoing segments. These code violations shall be forwarded as received or replaced by bad_code (see
`23.2.1.2) or /H/ (see 24.2.2.1) code-groups, as appropriate for the outgoing PHY type. Once a received code
`
`This is anzegchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`0225
`
`

`
`CSMA/CD
`
`IEEE
`Std 802.3u-1995
`
`violation has been replaced by bad_code or the /I-I/ code—group, this substitution shall continue for the
`remainder of the packet regardless of its content. The only exception to this rule is when contention exists
`among any of the ports, where the rules for collision handling (see 27.3.1.4) then take precedence.
`
`27.3.1.3 Received event-handling functional requirements
`
`27.3.1 .3.1 Received event handling
`
`For all its ports, the repeater set shall implement a fimction (scarrier_present) that represents a received
`event. Received events include both the data frame and any encapsulation of the data frame such as Pream-
`ble, SFD and the code—groups /H/, /J/, /K/, bad_code, eop, /T/, /R/, etc. A received event is exclusive of the
`IDLE pattern. Upon detection of scarrier_present from one port, the repeater set repeats all received signals
`in the data frame fi'om that port to the other port (or ports) as described in figure 27-2.
`
`27.3.1.3.2 Preamble regeneration
`
`The repeater set shall output preamble as appropriate for the outgoing PHY type followed by the SFD.
`
`27.3.1.3.3 Start-of-packet propagation delay
`
`The start-of-packet propagation delay for a repeater set is the time delay between the start of the packet (see
`24.6 and 23.11.3) on its repeated-fi‘om (input) port to the start of the packet on its repeated-to (output) port
`(or ports). This parameter is referred to as the SOP delay. The maximum value of this delay is constrained
`by table 27-2.
`
`27.3.1.3.4 Start-of-packet variability
`
`The start-of-packet variability for a repeater set is defined as the total worst-case difference between start-of-
`packet propagation delays for successive packets separated by 104 bit times (BT) or less at the same input
`port. The variability shall be less than or equal to those specified in table 27-1.
`
`Table 27-1 —Start-of-packet variability
`
`
`
`27.3.1.4 Collision-handling functional requirements
`
`27.3.1.4.1 Collision detection
`
`The repeater performs collision detection by monitoring all its enabled input ports for received events. When
`the repeater detects received events on more than one input port, it shall enter a collision state and transmit
`the Jam message to all of its output ports.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`0226
`
`

`
`IEEE
`Std 802.3u-1995
`
`27.3.1 .4.2 Jam generation
`
`SUPPLEMENT TO 802.3:
`
`While a collision is occurring between any of its ports, the repeater unit shall transmit the Jam message to all
`of the PMAs to which it is connected. The Jam message shall be transmitted in accordance with the repeater
`state diagram in figure 27-4 and figure 27-5.
`
`27.3.1.4.3 Collision-jam propagation delay
`
`The start-of-collision Jam propagation delay for a repeater set is the time delay between the start of the sec-
`ond packet input signals to arrive at its port and the start of Jam (see 24.6 and 23.11) out on all ports. This
`parameter is referred to as the SO] delay. The delay shall be constrained by table 27-2.
`
`Table 27-2—Start-of-packet propagation and start-of-collision Jam propagation delays
`
`27.3.1.4.4 Cessation-of-collision Jam propagation delay
`
`The cessation-of-collision Jam propagation delay for a repeater set is the time delay between the end of the
`packet (sec 24.6 and 23.113) that creates a state such that Jam should end at a port and the end of Jam (sec
`24.6 and 23.113) at that port. The states of the input signals that should cause Jam to end are covered in
`detail in the repeater state diagrams. This parameter is referred to as the EOJ delay. The delay shall be con-
`strained by table 27-3.
`
`Table 27-3—Cessation-of-collision Jam propagation delay
`
`27.3.1.5 Error-handling functional requirements
`
`27.3.1.5.1 100BASE-X carrier integrity functional requirements
`
`In l00BASE-TX and 100BASE-FX systems, it is desirable that the repeater set protect the network fiom
`some transient fault conditions that would disrupt network communications. Potential likely causes of such
`conditions are DTE and repeater power-up and power-down transients, cable disconnects, and faulty wiring.
`
`Each l00BASE-TX and 100BASE-FX repeater PMA interface shall contain a self-interrupt capability, as
`described in figure 27-9, to prevent a segment’s spurious carrier activity from reaching the repeater unit and
`hence propagating through the network.
`
`The repeater PMA interface shall count consecutive false carrier events. A false carrier event is defined as a
`carrier event that does not begin with a valid start-of-stream delimiter (see 24.2.2.l.4). The count shall be
`incremented on each false carrier event and shall be reset on reception of a valid carrier event. In addition,
`each PMA interface shall contain a false carrier timer, which is enabled at the beginning of a false carrier
`event and reset at the conclusion of such an event. A repeater unit shall transmit the Jam message to all of the
`PMAs to which it is connected for the duration of the false carrier event or until the duration of the event
`
`This is anzegchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`0227
`
`it 1025
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`Aerohive - Exhibit 1025
`0227
`
`

`
`CSMA/CD
`
`IEEE
`Std 802.3u-1995
`
`exceeds the time specified by the false_carrier_timer (see 27 .3.2.1.4), whichever is shorter. The Jam message
`shall be transmitted in accordance with the repeater state diagram in figure 27-4 and figure 27-5. The LINK
`UNSTABLE condition shall be detected when the False Carrier Count exceeds the value FCCLimit (see
`27.3.2.1.1) or the duration of a false carrier event exceeds the time specified by the false_carrier_timer. In
`addition, the LINK UNSTABLE condition shall be detected upon power-up reset.
`
`Upon detection of LINK UNSTABLE, the port shall perform the following:
`
`a)
`b)
`c)
`
`Inhibit sending further messages to the repeater unit.
`Inhibit sending further output messages from the repeater unit.
`Continue to monitor activity on that PMA interface.
`
`The repeater shall exit the LINK UNSTABLE condition when one of the following is met:
`
`a)
`
`The repeater has detected no activity (Idle) for more than the time specified by ipg_timer plus
`id1e_timer (see 27.3.2.1.4) on port X.
`b) A valid carrier event with a duration greater than the time specified by valid_carrier_timer (see
`27.3.2.1.4) has been received, preceded by no activity (Idle) for more than the time specified by
`ipg_timer (see 27.3.2.1.4) on port X.
`
`27.3.1.5.2 Speed handling
`
`If the PHY has the capability of detecting speeds other than 100 Mb/s, then the repeater set shall have the
`capability of blocking the flow of non-100 Mb/s signals. The incorporation of 100 Mb/s and 10 Mb/s
`repeater functionality within a single repeater set is beyond the scope of this standard.
`
`27.3.1.6 Partition functional requirements
`
`In large multisegment networks it may be desirable that the repeater set protect the network from some fault
`conditions that would disrupt network communications. A potentially likely cause of this condition could be
`due to a cable fault.
`
`Each repeater PMA interface shall contain a self-interrupt capability, as described in figure 27-8, to prevent a
`faulty segment’s carrier activity from reaching the repeater unit and hence propagating through the network.
`The repeater PMA interface shall count consecutive collisions. The count shall be incremented on each
`transmission that suffers a collision and shall be reset on a successful transmission. If this count exceeds the
`
`value CCLin1it (see 27.3.2.1.1) the Partition condition shall be detected.
`
`Upon detection of Partition, the port shall perform the following:
`
`a)
`b)
`c)
`
`Inhibit sending further input messages to the repeater unit.
`Continue to output messages from the repeater unit.
`Continue to monitor activity on that PMA interface.
`
`The repeater shall reset the Partition fi1nction when one of the following conditions is met:
`
`a)
`b)
`
`On power-up reset.
`The repeater has detected activity on the port for more than the number of bits specified for
`no_collision_tirner (see 27.3.2.1.4) without incurring a collision.
`
`27.3.1.7 Receive jabber functional requirements
`
`Each repeater PMA interface shall contain a self-interrupt capability, as described in figure 27-7, to prevent
`an illegally long reception of data fi'om reaching the repeater unit. The repeater PMA interface shall provide
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`0228
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`a window of duration jabber_tirner bit times (see 27.3.2.1.4) during which the input messages may be passed
`on to other repeater unit functions. If a reception exceeds this duration, the jabber condition shall be
`detected.
`
`Upon detection ofjabber, the port shall perform the following:
`
`a)
`b)
`
`Inhibit sending filrther input messages to the repeater 11nit.
`Inhibit sending further output messages from the repeater unit.
`
`The repeater PMA interface shall reset the Jabber function and re-enable data transmission and reception
`when either one of the following conditions is met:
`
`On power-up reset.
`a)
`b) When carrier is no longer detected.
`
`27.3.2 Detailed repeater functions and state diagrams
`
`A precise algorithmic definition is given in this subclause, providing a complete procedural model for the
`operation of a repeater, in the form of state diagrams. Note that whenever there is any apparent ambiguity
`concerning the definition of repeater operation, the state diagrams should be consulted for the definitive
`statement.
`
`The model presented in this subclause is intended as a primary specification of the functions to be provided
`by any repeater unit. It is important to distinguish, however, between the model and a real implementation.
`The model is optimized for simplicity and clarity of presentation, while any realistic implementation should
`place heavier emphasis on such constraints as efliciency and suitability to a particular implementation tech-
`nology.
`
`It is the functional behavior of any repeater unit implementation that shall match the standard, not the inter-
`nal structure. The intemal details of the procedural model are usefiil only to the extent that they help specify
`the external behavior clearly and precisely. For example, the model uses a separate Receive Port Jabber state
`diagram for each port. However, in actual implementation, the hardware may be shared.
`
`The notation used in the state diagram follows the conventions of 1.2.1. Note that transitions shown without
`source states are evaluated at the completion of every state and take precedence over other transition condi-
`tions.
`
`27.3.2.1 State diagram variables
`
`27.3.2.1.1 Constants
`
`CCLimit
`
`The number of consecutive collisions that must occur before a segment is partitioned.
`
`Values: Positive integer greater than 60.
`FCCLimit
`
`The number of consecutive False Carrier events that must occur before a segment is isolated.
`Value:
`2.
`
`This is anzfirchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`0229
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`

`
`CSMA/CD
`
`27.3.2.1 .2 Variables
`
`activity(Port designation)
`
`IEEE
`Std 802.3u-1995
`
`Indicates port activity status. The repeater core effects a summation ofthis variable received flom
`all its attached ports and responds accordingly.
`
`Values:
`
`0; no flame or packet activity at any port.
`1; exactly 1 port of the repeater set has frame or packet activity input.
`>1; more than 1 port of the repeater set has flame or packet activity input. Altemately,
`one or more ports has detected a carrier that is not valid.
`
`all_data_sent
`
`Indicates if all received data flame bits or code-groups flom the current flame have been sent.
`During or after collision the all_data_sent variable follows the inverse of the carrier of port N.
`
`Values:
`
`true; all received data flame bits or code-groups have been sent.
`false; all received data frame bits or code-groups have not been sent.
`
`begin
`
`The Interprocess flag controlling state diagram initialization values.
`Values:
`true
`false
`
`ca1rier_status(X)
`
`Signal received from PMA; indicates the status of sourced Carrier input at port X.
`
`Values: ON; the cam'er_status parameter of the PMA_CARRlER.indicate primitive for port X
`is ON.
`OFF; the cam'er_status parameter of the PMA_CARRIER.indicate primitive for port X
`is OFF.
`
`data_ready
`
`Indicates if the repeater has detected and/or decoded the MAC SFD and is ready to send the
`received data.
`
`Values:
`
`true; the MAC SFD has been detected and/or decoded.
`false; the MAC SFD has not been detected nor decoded.
`
`force_jam(X)
`
`Flag flom Carrier Integrity state diagram for port X, which determines whether all ports should
`transmit Jam.
`
`Values:
`
`true; the Carrier Integrity Monitor has determined that it requires all ports be forced to
`transmit Jam.
`false; the Carrier Integrity Monitor has determined that it does not require all ports be
`forced to transmit Jam.
`
`Default:
`
`for T4 ports: false
`
`isolate(X)
`
`Flag flom Carrier Integrity state diagram for port X, which determines whether a port should be
`enabled or disabled.
`
`Values:
`
`true; the Carrier Integrity Monitor has determined the port should be disabled.
`false; the Carrier Integrity Monitor has determined the port should be enabled.
`
`jabber(X)
`
`Flag flom Receive Timer state diagram for port X which indicates that the port has received
`excessive length activity.
`
`Values:
`
`true; port has exceeded the continuous activity limit.
`false; port has not exceeded the continuous activity limit.
`
`link_status(X)
`
`Signal received flom PMA; indicates link status for port X (see 23.1.4.5 and 24.3.1.5).
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`0230
`
`'t 1025
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`Aerohive - Exhibit 1025
`0230
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`opt(X)
`
`OUT(X)
`
`Values: OK; the link_status parameter of the PMA_LINK.indicate primitive for port X is OK.
`READY; the 1ink_status parameter of the PMA_L1NK. indicate primitive for port X is
`READY.
`FAIL; the link_status parameter of the PMA_LINK.indieate primitive for port X is
`FAIL.
`
`Implementation option. Either value may be chosen for repeater implementation.
`
`Values:
`
`true; port will emit the .TamT4 pattern in response to collision conditions.
`false; port will append Jam pattern after preamble and SFD in response to collision
`conditions.
`
`Type of output repeater is sourcing at port X.
`
`Values:
`
`Idle; repeater is transmitting an IDLE pattern as described by 23.4.1.2 or 24.2.2.1.2.
`In(N); repeater is transmitting rx_code_bit(s) as received from port (N) except /J/K/ (see
`24.3.4.2).
`Pream; repeater is sourcing preamble pattern as defined by the PMA or PCS of the port
`type (see 23.2.1.2, 24.2.2.2, figure 23-6, and figure 24-5).
`Data; repeater is transmitting data frame on port X. This data represents the original
`MAC source data field, properly encoded for the PHY type (see 23.2.1.2 and 24.2.2.2).
`Jam; repeater is sourcing well formed arbitrary data encodings, excluding SFD, to the
`port PMA.
`JamX; repeater is sourcing the pattern 010l01... repetitively on port X.
`JamT4; repeater is sourcing the pattern +—+—... repetitively on port X
`SFD; repeater is sourcing the Start Frame Delimiter on port X encoded as defined by the
`appropriate PHY (see 23.2.3 and figure 24-5).
`/J/K/; repeater is sourcing the code-groups /J/K/ as defined by the PMA on port X (see
`24.2.2.1.4).
`/T/R/; repeater is sourcing the code-groups /T/R/ as defined by the PMA on port X (see
`24.2.2.1 .5).
`DF; repeater is sourcing the data flame of the packet on port X. These are code elements
`originating on port N exclusive of EOP1-5, SOSA, and SOSB (see 23.2.3 and 23.2.4).
`EOP; repeater is sourcing end-of-packet delimiter (EOPI-5) as defined by the
`appropriate PMA on port X (see 23.2.1.2 and 23.2.4.1).
`bad_code; repeater is sourcing bad_code as defined by the PMA ofthe transmit port (see
`23 .2.4. 1 ).
`tx_err; repeater is sourcing a transmit error code element, either bad_code (see 23.2.4.1)
`or the code—group /I-I/ (see 24.2.2.1) as appropriate to the outgoing PHY type.
`
`partitionO()
`
`Flag from Partition state diagram for port X, which determines whether a port receive path should
`be enabled or disabled.
`
`Values:
`
`true; port has exceeded the consecutive collision limit.
`false; port has not exceeded the consecutive collision limit.
`
`This is arizfirchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
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`
`

`
`CSMA/CD
`
`rxerror_status(X)
`
`IEEE
`Std 802.3u-1995
`
`Signal received from PMA; indicates if port X has detected an error condition from the PMA (see
`23.3.7.1 and figure 24-14). The repeater need not propagate this error condition during collision
`events.
`
`Values: ERROR; the rxerror_status parameter of the PMA_RXERROR.indicate primitive for
`port X is ERROR.
`NO_ERROR; the rxerror_status parameter of the PMA_RXERROR.indicate primitive
`for port X is NO_ERROR.
`
`RX_ER(X)
`
`Signal received from PCS; indicates if port X has detected an error condition from the PCS (see
`23.2.1.4, 24.2.3.2, figure 23-10, and figure 24-11). The repeater need not propagate this error
`condition during collision events.
`
`Values:
`
`true; the PCS RX_ER signal for port X is asserted.
`false; the PCS RX_ER signal for port X is negated.
`
`scarrier_present(X)
`
`Signal received fiom PMA; indicates the status of sourced Carrier input at port X.
`
`Values:
`
`true; the carrier_status parameter of the PMA_CARRlER.indicate primitive for port X
`is ON.
`false; the carrier_status parameter of the PMA_CARRIER.indicate primitive for port X
`is OFF.
`
`s0urce_type(X)
`
`Signal received from PMA; indicates PMA type for port X. The first port to assert activity
`maintains the source type status for all transmitting port(s) until activity is deasserted. Repeaters
`may optionally force nonequality on comparisons using this variable. It must then follow the
`behavior of the state diagrams accordingly and meet all the delay parameters as applicable for the
`real implemented port type(s).
`
`Values:
`
`FXTX; the pma_type parameter of the PMA_TYPE.indicate primitive for port X is X.
`T4; the pma_type parameter of the PMA_TYPE.indicate primitive for port X is T4.
`
`27.3.2.1.3 Functions
`
`command(X)
`
`A function that passes an inter-process flag to all ports specified by X.
`
`Values:
`
`copy; indicates that the repeater core has summed the activity levels of its active ports
`and is in the ACTIVE state.
`collision; indicates that the repeater core has summed the activity levels of its active
`ports and is in the JAM state.
`quiet; indicates that the repeater core has summed the activity levels of its active ports
`and is in the IDLE state.
`
`port(Test)
`
`A fimction that returns the designation of a port passing the test condition. For example,
`port(activity = scarrier_present) returns the designation: X for a port for which scarrier_present =
`true. If multiple ports meet the test condition, the Port function will be assigned one and only one
`of the acceptable values.
`
`27.3.2.1.4 Timers
`
`All timers operate in the same fashion. A timer is reset and starts timing upon entering a state where “start
`x_timer” is asserted. At time “X” after the timer has been started, “x_timer_done” is asserted and remains
`asserted until the timer is reset. At all other times, “x_timer_not_done” is asserted.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`0232
`
`it 1025
`
`Aerohive - Exhibit 1025
`0232
`
`

`
`IEEE
`Std 802.3u-1995
`
`SUPPLEMENT TO 802.3:
`
`When entering a state where “start x_timer” is asserted, the timer is reset and restarted even if the entered
`state is the same as the exited state.
`
`The timers used in the repeater state diagrams are defined as follows:
`
`false_carrier_timer
`
`Timer for length of false carrier (27 .3.1.5. 1) that must be present before the ISOLATION state is
`entered. The timer is done when it reaches 450 — 500 BT.
`
`idle_timer
`
`Timer for length of time without carrier activity that must be present before the ISOLATION state
`is exited (27 .3.l.5.1). The timer is done when it reaches 33 000 :|: 25% BT.
`
`ipg_timer
`
`Timer for length of time without carrier activity that must be present before carrier integrity tests
`(27.3.l.5 .1) are re-enabled. The timer is done when it reaches 64 — 86 BT.
`
`jabber_timer
`
`Timer for length of carrier which must be present before the Jabber state is entered (27.3 . l .7). The
`timer is done when it reaches 40 000 — 75 000 BT.
`
`no_co11ision_timer
`
`Timer for length ofpacket without collision before the Partition state is exited (27.3.1.6). The timer
`is done when it reaches 450 — 560 BT.
`
`valid_ca1rier_timer
`
`Timer for length of valid carrier that must be present before the Isolation state is exited
`(27.3.1.5.1). The timer is done when it reaches 450 — 500 BT.
`
`27.3.2.1.5 Counters
`
`cc(x)
`
`FCC(X)
`
`Consecutive port collision count for port X. Partitioning occurs on a terminal count of CCLimit
`being reached.
`
`Values: Non-negative integers up to a terminal count of CCLimit.
`
`False Carrier Counter for port X. Isolation occurs on a terminal count of FCCLimit being reached.
`
`Values: Non-negative integers up to a terminal count of FCCLimit.
`
`27.3.2.1.6 Port designation
`
`Ports are referred to by number. Port information is obtained by replacing the X in the desired function with
`the number of the port of interest. Ports are referred to in general as follows:
`
`X
`
`N
`
`ALL
`
`Generic port designator. When X is used in a state diagram, its value is local to that diagram and
`not global to the set of state diagrams.
`
`Is defined by the Port function on exiting the IDLE or JAM states of figure 27-2. It indicates a port
`that caused the exit from these states.
`
`Indicates all repeater ports are to be considered. All ports shall meet test conditions in order for the
`test to pass.
`
`This is anzfirchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`
`
`Aerohive - Exhibit 1025
`0233
`
`

`
`CSMA/CD
`
`ALLXN
`
`ANY
`
`IEEE
`Std 802.3u-1995
`
`Indicates all ports except N should be considered. All ports considered shall meet the test
`conditions in order for the test to pass.
`
`Indicates all ports are to be considered. One or more ports shall meet the test conditions in order
`for the test to pass.
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`it 1025
`
`0234
`
`Aerohive - Exhibit 1025
`0234
`
`

`
`IEEE
`Std 8D2_3u—1995
`
`27.3.2.2 Stale diagrams
`
`SUPPLEMENT TO 802.3:
`
`Ii
`
`START
`
`begin c= we
`
`1
`
`i
`
`IDLE
`
`command(ALL) c= quiet
`begin -:= false
`
`aclivity(ALL) = 1
`
`acliVity(ALL) >1
`
`V
`
`ASSIGN
`
`N .= poI1(activity(:1))
`
`LUCT
`
`ACTIVE
`
`command(ALLXN) -:= copy
`i:ommand(N)-:= quiet
`
`JAM
`
`command(ALL) c= collision
`
`(a{;[ivity{A|_L] = 0) ¢
`(aI|_data_sent = true)
`
`activity{ALL) > 1
`
`activity{ALL) : 1
`
`activity(ALL) : {J
`
`Figure 27-2—Repeater core state diagram
`
`This is arigfigrchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`Aerohive - Exhibit
`
`Aerohive - Exhibit 1025
`0235
`
`

`
`CSMNCD
`
`IEEE
`Std Bl]2_3u—1995
`
`(jabber{X) : hue) +
`[iso!ate{X) = true) +
`[link_status(X) : UK) +
`(P3|'fifi0"(X) = true]
`
`begin = true
`
`SILENT
`
`activity(X) e: 0
`
`scarrierJ)resent=true i
`
`ATFENTION
`aclivity(X) «:= 1
`source_type(X)c: PortType
`
`forceJam()()=truei
`
`FORCE ATFENTION
`
`scarrierJ)resen1 = false
`
`activ'rly()(] 4: 2
`
`scarrierJ)resent = false
`
`Figure 27-3—Receive state diagram for port X
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this stangl1a;rd.
`
`Aerohive - Exhibit 1025
`0236
`
`

`
`IEEE
`Std 8D2_3u—1995
`
`SUPPLEMENT TO 802.3:
`
`(jabber(X} = true) +
`(iso1ate(X) = true) +
`
`(linl(_5tatus{X) at OK)
`
`begin 2 we
`
`(I:ommand(X)=collision)+
`
`(command(X) = copy)
`
`HEADER
`.
`[0UT(X} ¢= IJJKI
`(comrnand(X) = quiet) *
`(if S-0urI=e_IrDe(N} = FXTXH
`mo SENT
`[OUT{)() .:= Pream 5. SFD
`(if sourI:e_type(N) at FXT)(}]
`
`l
`
`QUIET
`ourrx) ¢= Idle
`
`(oomrnandfx) = collision) t
`LHK! SENT
`
`(Pream 8. SFD SENT] +
`((!Jll(I SENT) *
`{source_type(N) = FXTX) *
`:[oomrn.and(X) = copy))
`
`REPEAT DATA
`
`[OUT(X) <= ln(N)
`(If 5ouroe_type(N) = FXTXJ]
`[OUT(X) : Daia
`(If 5ouroe_type(N) =E FXTXJ]
`
`tflmeiwpetn} : FXTX) *
`(aII_oata_sent = true)
`
`oomrnand(x) = copy
`
`commandpt) = collision
`
`COLLISION
`
`[0UT(X) c: Jamx
`_
`(" 5°”"""—tV9""") : FXTXH
`[0UT(X) C: Jam
`(ii 50Urce_tvve(N) == F1500}
`
`(S0U"3e_M1B(N}¥ FXTX) *
`
`lD0m"13nfl(X)= quiet}
`
`ab
`(s.ourr:e_type(N) = FXTX) z
`
`(command{)() = quiet)
`
`(5ource_type(N) = FXTX) *
`{aIl_data_5ent = lIue)
`
`TRAILER
`
`ourrx) ¢= ma:
`
`l ITIRJSENT
`
`Figure 27-4—100BASE-TX and 100BASE-FX transmit state diagram for port X
`
`This is arrgfirchive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`Aerohive - Exhi
`
`Aerohive - Exhibit 1025
`0237
`
`

`
`CSMNCD
`
`IEEE
`Std B[|2_3u—1995
`
`(iahberpt) = true) +
`(isolatefx) = tme) +
`(|ink_statu5()() at OK}
`
`({comrnand(X) : collision) s
`(opt = false)) +
`(cumrnand(X) = copy)
`
`HEADER
`I
`ourixi : Pream s. SFD
`
`oomrnand(X) = quiet
`
`QUIET
`OUT(X) ¢: Idle
`
`(I:ommand(X) = ooliision) *
`
`(opt =true) 2
`(source_lype(N) = T4)
`
`(commandtx) = collision) *
`mm = true)
`EASYJAM
`
`F‘
`
`ouroq ¢= JamT4
`
`(cumn1and(X} = ooilision} «t
`(opt = false) is
`(Pream & SFD SENT} it
`(5ouri:e_ype(N)¢ T4)
`
`(Pream & SFD SENT) t
`twmmandix) = WW”
`
`REPEAT DATA
`
` ,
`
`oommand(X) = quiet
`
`i:ommand()() = ooltrsion
`[OUT(X) c: DF
`(‘rt source_type(N) = Tz1)] ' C0'—'—'5'0N
`[0UT{X) <= Data
`Ounx} (2 Jam
`(i1 source_typ-e(N) ;:T4)]
`
`‘Source twem) $1.4) *
`(air_data_sent = true)
`
`
`
` Dl commanu{X} = quiet
`
`TR.A!LER
`
`(source_lype(N) = T4} at
`(aIl_dai.a_5eni = true)
`
`OUT(X) <= EOP
`
`L EOP SENT
`
`Figure 2?-5—100BASE-T4 transmit state diagram for port X
`
`This is an Archive IEEE Standard.
`
`It has been superseded by a later version of this standard.
`
`Aerohive - Exhib
`
`Aerohive - Exhibit 1025
`0238
`
`

`
`IEEE
`Std 8D2_3u—1995
`
`SUPPLEMENT TO 802.3:
`
`begin = irue
`
`Hi
`
`NO SOURCE DATA
`
`Data c: Jam
`DF -:= Jam
`
`RX_ER (N) = true +
`rxerror_status(N) = ERROR
`
`data-ready Z We
`
`ll
`
`E R RQR
`
`RE PEAT
`
`Data <= tx_enor
`DF c: bad_code
`
`Data "= D3t3(N)
`DF <= DF(N)
`
`RX_ER(N) = false *
`rxerro!_status(N) = NO_ERROR e
`(command{ALL) = quiet +
`c0mmand(ALL) = collision)
`
`RX_ER (N) = true +
`rxerr0r_status(N] = ERROR
`
`c0mmand(ALL) = quiet
`
`com