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# VNIP Parameters

#### Initialization Timer

#### Receive Timer

#### Transmit Delay Frequency

#### Transmit Timer

#### VNIP Mode

#### VNIP Transmit Delay Table

  These parameters enable you to configure parameters associated with the Probe's Virtual Network Interactive Protocol (VNIP) topology and transit delay operations.
  VNIP topology is responsible for compiling topographical information on DLCI circuits passing through the unit's DTE and network ports. This information provides the network manager with a topology "map" of probe nodes having a presence on each DLCI circuit.
  VNIP transit delay is responsible for compiling round-trip transit delay statistics on circuit segments or "hops" which connect each probe node.
  Note: Transit delay statistics can only be calculated on circuit segments (hops) that have been previously mapped by VNIP topology. To allow VNIP topology messages to pass through a node device without the unit actually being included in the topology, configure the unit for VNIP mode = Inactive Configuring Dedicated/CBO mode without Slip management will cause loss of contact with unit.

#### VNIP Mode

  Options in this list vary depending upon the type of unit you are configuring.
  If set to Inactive, the unit will not respond to VNIP "hello" messages and will not appear in any VNIP topologies.
  If set to DTE, VNIP on the unit's DTE port will be enabled. A topology database will be compiled based on devices whose VNIP protocols are enabled on the unit's DTE side. VNIP "hello" and topology messages will not be sent out on the DDS network port.
  If set to DDS, VNIP on the unit's DDS port will be enabled. A topology database will be compiled based on devices whose VNIP protocols are enabled on the unit's DDS side. VNIP "hello" and topology messages will not be sent out the DTE port.
  If set to Both, VNIP on the unit's To-DTE and To-DCE ports will be enabled. (S-FRAP 3.0 Only)
  If set to Both, VNIP on the unit's DDS and DTE ports will be enabled. A topology database will be compiled based on devices whose VNIP protocols are enabled on the unit's DDS side. VNIP "hello" and topology messages will be sent out the DTE port.(Other Models)
  If set to To-DTE, VNIP on the unit will be set to send to a DTE port.
  If set to To-DCE, VNIP on the unit will be set to send to a DTE port.
  If set to T1, VNIP on the unit's T1 port will be enabled. A topology database will be compiled based on devices whose VNIP protocols are enabled on the unit's T1 side. VNIP "hello" and topology messages will not be sent out on the DTE port.
  Range: Inactive, DTE, DDS, T1, or Both (DTE and DDS, or DTE and T1, depending upon the type of Probe you are configuring)

#### Initialization Timer

  The value in this field represents the interval at which the unit's database is checked for newly-activated DLCIs. Once a new DLCI is detected, a VNIP topology "hello" message is sent via this new path in an attempt to establish VNIP topology communications with all nodes present on the DLCI. The initialization timer does not check for a response to its "hello".
  The direction or port through which the "hello" is sent is determined by the VNIP Mode setting.
  The message includes only that portion of the topology database that it has learned concerning itself and neighbors located on the reverse interface of the same virtual circuit and not the entire VNIP topology database.
  The lower this setting is, the more frequently topology messages are transmitted. To minimize topology traffic, you may want to set the timer to a higher value.
  Range: 5 -- 86400 seconds

#### Transmit Timer

  This timer maintains VNIP topology communications with network neighbors having a presence on the virtual circuit. This timer controls how often the local unit sends topology messages to each virtual circuit network neighbor via their respective DLCI.
  The topographical information contained in each message applies only to the virtual DLCI circuit on which the message is sent. This information is used by network neighbors to update their own VNIP topology database. Similarly, VNIP messages received from network neighbors (at their transmit timer rate) updates the local unit's topology database. The direction, or port through which the VNIP message is sent is determined by the VNIP Mode setting.
  Range: 5 -- 86400 seconds

#### Receive Timer

  The value in this field (in seconds) represents how often a VNIP topology message are expected to be received by the unit's neighbors. The topology message should be received on each virtual circuit at the rate determined by each unit's transmit timer value. If the receive timer expires without receiving the expected topology message, the unit will transmit an initialization "hello" on the affected PVC in an attempt to reestablish VNIP communications.
  To minimize "hello" traffic, it is recommended that this timer value be set to three times the transmit timer rate (Rx = 3X Tx timer rate).
  Range: 5 -- 86400 seconds

#### Transmit Delay Frequency

  This table enables you to configure the parameters associated with compiling transit delay measurements on DLCI circuits found in the VNIP topology database.
  Unlike the VNIP topology, which automatically identifies DLCIs and collects virtual circuit information (if enabled), DLCI circuits, on which transit delay statistics are compiled, must be defined individually.
  Range: 15-604800

#### VNIP Transmit Delay Table

  Note: The VNIP Transit Delay Table contains sufficient line entries for all DLCIs included in VNIP topographies compiled on the DTE port and network port (VNIP Mode = Both). Transit delay statistics can only be calculated on circuit segments (hops) which have been previously mapped by VNIP topology.
  ID identifies the VNIP transit delay table entry. The numbers listed in this field column are used to index table entries. An ID number only appears for corresponding transit delay entries.
  Range: 1-32 (FRAP 3.0 Only)
  Range: 1-100 (S-FRAP 3.0 and T-FRAP 3.0 Only)
  Range: 1-16 (Other Models)
  DLCI Interface identifies the VNIP port topography (DTE or network) that contains the DLCI circuit on which you want to calculate transit delays.
  Note: If you want to calculate transit delays on a DLCI that appears in both VNIP port topographies (DTE and Network), you must enter two separate table entries. Each table entry identifies a different interface port for the same DLCI value.
  Range: DTE or DDS (D-FRAP 3.0)
  Range: To-DTE or To-DCE (S-FRAP 3.0)
  Range: DTE or T1 (T-FRAP 3.0)
  Range: DTE, DDS, or T1 (Other Models)
  DLCI Value identifies the virtual DLCI circuit on which you want to calculate VNIP transit delays. The DLCI identified by this value must appear in the VNIP port topography identified by DLCI Interface.
  Range: 0 -- 1023
  Number of Hops specifies VNIP transit delay hops. The term "hops" applies to virtual DLCI circuits segments between network devices.
  0 -- Transit delays are calculated on all hops associated with the virtual circuit identified by DLCI Value.
  1 -- 254 -- A transit delay is calculated for the user-defined hop associated with the virtual circuit identified by DLCI Value.
  255 -- A transit delay will be calculated for only the furthest hop associated with the virtual circuit identified by DLCI Value.
  Range: 0, 1-254, or 255
  Rx Summary Cancel specifies the VNIP transit delay receive summary cancellation state (RSC).
  Enable -- The unit will use the information contained in received summary messages to update (on a DLCI-by-DLCI basis) its own VNIP transit delay database. The unit will not send out a transit request message, on the virtual DLCI circuit from which it received the summary message, if it received the summary message before the transit delay frequency timer expires.
  Disable -- The unit will ignore the transit delay information contained in any received summary message. The unit will always send out transit delay request messages at the frequency rate and update its own VNIP transit delay database using calculations compiled through the exchange of transit delay request and reply messages.
  Range: Enable or Disable
  Threshold specifies a transit delay threshold for the virtual circuit associated with this DLCI. If the round-trip delay for any segment (hop) within the virtual circuit equals or exceeds this value, a Trap message is sent to notify the network manager that the transit delay for that specific DLCI has reached its threshold.
  Range: 1 -- 86,400,000 milliseconds (24 hours)
  Note: VNIP transit delays stop calculating deleted entries once the unit's configuration is updated.