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Logical Link Control, type 2 (LLC2) protocol provides connection-oriented service and is widely used in LAN environments, particularly among IBM communication systems connected by Token Ring. The Cisco IOS software supports LLC2 connections over Ethernet, Token Ring, and Fiber Distributed Data Interface (FDDI).
The LLC2 commands provide operations that support the following features:
SDLC is used as the primary Systems Network Architecture (SNA) link-layer protocol for WAN links. SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then transmit if they have outgoing data. When configured as primary and secondary nodes, routers are established as SDLC stations.
The SDLC commands described in this chapter pertain to routers configured as SDLC stations. This is in contrast to a device configured for SDLC Transport where the router is not configured as an SDLC station, but acts as an intermediary, passing SDLC frames between two SDLC stations across a mixed-media, multiprotocol environment.
The SDLC commands support the following features:
Use the commands in this chapter to adjust the LLC2 and SDLC parameters. For LLC2 and SDLC parameter configuration information and examples, refer to the "Configuring LLC2 and SDLC Parameters" chapter in the Bridging and IBM Networking Configuration Guide.
Use the encapsulation sdlc interface configuration command to configure an SDLC interface.
encapsulation sdlcSyntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
The encapsulation sdlc command must be used to configure an SDLC interface if you plan to implement DLSw+ or Frame Relay access support.
SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then transmit if they have outgoing data. When configured as primary and secondary nodes, our routers are established as SDLC stations. Use the sdlc role interface configuration command to establish the role as primary or secondary.
In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.
If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to a FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.
Examples
The following example configures an SDLC interface:
interface serial 2/6 no ip address encapsulation sdlc
Related Commands
Establishes the router to be either a primary or secondary SDLC station.
Command
Description
Use the encapsulation sdlc-primary interface configuration command to configure the router as the primary SDLC station if you plan to configure the SDLLC media translation feature.
encapsulation sdlc-primarySyntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
The encapsulation sdlc-primary or encapsulation sdlc-secondary command must be used to configure an SDLC interface. To use the encapsulation sdlc-primary command, first select the interface on which you want to enable SDLC. Then establish the router as a primary station. Next, assign secondary station addresses to the primary station using the sdlc address command.
SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then transmit if they have outgoing data. When configured as primary and secondary nodes, our routers are established as SDLC stations.
In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.
If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to an FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.
Examples
The following example shows configures serial interface 0 on your router to allow two SDLC secondary stations to attach through a modem-sharing device (MSD) with addresses C1 and C2:
! enter a global command if you have not already interface serial 0 encapsulation sdlc-primary sdlc address c1 sdlc address c2
Related Commands
Configures the router as a secondary SDLC station if you plan to configure the SDLLC media translation feature. Assigns a set of secondary stations attached to the serial link. Displays the LLC2 connections active in the router.
Command
Description
Use the encapsulation sdlc-secondary interface configuration command to configure the router as a secondary SDLC station if you plan to configure the SDLLC media translation feature.
encapsulation sdlc-secondarySyntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
An encapsulation sdlc-primary or encapsulation sdlc-secondary command must be used to configure an SDLC interface. To use the encapsulation sdlc-secondary command, first select the interface on which you want to enable SDLC. Then establish the router as a secondary station. Next, assign secondary station addresses to the primary station using the sdlc address command.
SDLC defines two types of network nodes: primary and secondary. Primary nodes poll secondary nodes in a predetermined order. Secondaries then transmit if they have outgoing data. When configured as primary and secondary nodes, our devices are established as SDLC stations.
In the IBM environment, a front-end processor (FEP) is the primary station and establishment controllers (ECs) are secondary stations. In a typical scenario, an EC may be connected to dumb terminals and to a Token Ring network at a local site. At the remote site, an IBM host connects to an IBM FEP, which can also have links to another Token Ring LAN. Typically, the two sites are connected through an SDLC leased line.
If a router is connected to an EC, it takes over the function of the FEP, and must therefore be configured as a primary SDLC station. If the router is connected to a FEP, it takes the place of the EC, and must therefore be configured as a secondary SDLC station.
Examples
The following example establishes the router as a secondary SDLC station:
interface serial 0 encapsulation sdlc-secondary
Related Commands
Configures the router as the primary SDLC station if you plan to configure the SDLLC media translation feature. Assigns a set of secondary stations attached to the serial link. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 ack-delay-time interface configuration command to set the amount of time the Cisco IOS software waits for an acknowledgment before sending the next set of information frames.
llc2 ack-delay-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software allows incoming information frames to stay unacknowledged. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 100 milliseconds.
Defaults
100 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Upon receiving an information frame, each LLC2 station starts a timer. If the timer expires, an acknowledgment will be sent for the frame, even if the llc2 ack-max number of received frames has not been reached. Experiment with the value of the llc2 ack-delay-time command to determine the configuration that balances acknowledgment network overhead and quick response time (by receipt of timely acknowledgments).
Use this command in conjunction with the llc2 ack-max command to determine the maximum number of information frames the Cisco IOS software can receive before sending an acknowledgment.
Examples
In the following example, the software allows a 100-millisecond delay before I-frames must be acknowledged:
! enter a global command, if you have not already interface tokenring 0 ! sample ack-max command llc2 ack-max 3 ! allow a 100 millisecond delay before I-frames must be acknowledged llc2 ack-delay-time 100
At time 0, two information frames are received. The llc2 ack-max amount of three has not been reached, so no acknowledgment for these frames is sent. If a third frame, which would force the software to send an acknowledgment, is not received in 100 milliseconds, an acknowledgment will be sent anyway, because the llc2 ack-delay timer expires. At this point, because all frames are acknowledged, the counter for the ack-max purposes will be reset to zero.
Related Commands
Controls the maximum amount of information frames the Cisco IOS software can receive before it must send an acknowledgment. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 ack-max interface configuration command to control the maximum amount of information frames the Cisco IOS software can receive before it must send an acknowledgment.
llc2 ack-max packet-count
Syntax Description
packet-count Maximum number of packets the software will receive before sending an acknowledgment. The minimum is 1 packet and the maximum is 127 packets. The default is 3 packets.
Defaults
3 packets
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
An LLC2-speaking station can send only a predetermined number of frames before it must wait for an acknowledgment from the receiver. If the receiver waits until receiving a large number of frames before acknowledging any of them, and then acknowledges them all at once, it reduces overhead on the network.
For example, an acknowledgment for five frames can specify that all five have been received, as opposed to sending a separate acknowledgment for each frame. To keep network overhead low, make this parameter as large as possible.
However, some LLC2-speaking stations expect this to be a low number. Some NetBIOS-speaking stations expect an acknowledgment to every frame. Therefore, for these stations, this number is best set to 1. Experiment with this parameter to determine the best configuration.
Examples
In the following example, the software is configured to receive up to seven frames before it must send an acknowledgment. Seven frames is the maximum allowed by SNA before a reply must be received:
! enter a global command, if you have not already interface tokenring 0 ! receive up to seven frames before sending an acknowledgment llc2 ack-max 7 ! sample delay-time command llc2 ack-delay-time 100
Related Commands
Sets the amount of time the Cisco IOS software waits for an acknowledgment before sending the next set of information frames. Controls the maximum number of information frames the Cisco IOS software sends before it waits for an acknowledgment. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 idle-time interface configuration command to control the frequency of polls during periods of idle time (no traffic).
llc2 idle-time milliseconds
Syntax Description
milliseconds Number of milliseconds that can pass with no traffic before the LLC2 station sends a Receiver Ready frame. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 10000 milliseconds.
Defaults
10000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Periodically, when no information frames are being transmitted during an LLC2 session, LLC2 stations are sent a Receiver Ready frame to indicate they are available. Set the value for this command low enough to ensure a timely discovery of available stations, but not too low, or you will create a network overhead with too many Receiver Ready frames.
Examples
In the following example, the Cisco IOS software waits 20000 milliseconds before sending a Receiver Ready ("are you there") frame:
! enter a global command, if you have not already
interface tokenring 0 ! wait 20000 milliseconds before sending receiver-ready frames llc2 idle-time 20000
Related Commands
Controls the amount of time the Cisco IOS software waits until repolling a busy remote station. Sets the amount of time the Cisco IOS software waits for a final response to a poll frame before resending the poll frame. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 local-window interface configuration command to control the maximum number of information frames the Cisco IOS software sends before it waits for an acknowledgment.
llc2 local-window packet-count
Syntax Description
packet-count Maximum number of packets that can be sent before the software must wait for an acknowledgment. The minimum is 1 packet and the maximum is 127 packets. The default is 7 packets.
Defaults
7 packets
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
An LLC2-speaking station can send only a predetermined number of frames before it must wait for an acknowledgment from the receiver. Set this number to the maximum value that can be supported by the stations with which the router communicates. Setting this value too large can cause frames to be lost, because the receiving station may not be able to receive all of them.
Examples
In the following example, the software will send as many as 30 information frames through Token Ring interface 1 before it must receive an acknowledgment:
! enter a global command, if you have not already interface tokenring 1 llc2 local-window 30
Related Commands
Controls the maximum amount of information frames the Cisco IOS software can receive before it must send an acknowledgment. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 n2 interface configuration command to control the amount of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations.
llc2 n2 retry-count
Syntax Description
retry-count Number of times the software retries operations. The minimum is 1 retry and the maximum is 255 retries. The default is 8 retries.
Defaults
8 retries
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
An LLC2 station must have some limit to the number of times it will resend a frame when the receiver of that frame has not acknowledged it. After the software is told that a remote station is busy, it will poll again based on the retry-count value. When this retry count is exceeded, the LLC2 station terminates its session with the other station. Set this parameter to a value that balances between frame checking and network performance.
Examples
In the following example, the software will resend a frame up to four times through Token Ring interface 1 before it must receive an acknowledgment. Because you generally do not need to change the retry limit, this example shows you how to reset the limit to the default of 8.
! enter a global command, if you have not already interface tokenring 1 ! retry value of 8 llc2 n2 8
Related Commands
Controls the amount of time the Cisco IOS software will wait before resending unacknowledged information frames. Controls the amount of time the Cisco IOS software waits until repolling a busy remote station. Controls the amount of time the Cisco IOS software waits for a correct frame after sending a reject command to the remote LLC2 station. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 t1-time interface configuration command to control the amount of time the Cisco IOS software will wait before resending unacknowledged information frames.
llc2 t1-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software waits before resending unacknowledged information frames. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 1000 milliseconds.
Defaults
1000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Use this command in conjunction with the llc2 n2 command to provide a balance of network monitoring and performance. Ensure that enough time is allowed to account for the round trip between the router and its LLC2-speaking stations under heavy network loading conditions.
Examples
In the following example, the software will wait 4000 milliseconds before resending an unacknowledged frame through Token Ring interface 2:
! enter a global command, if you have not already interface tokenring 2 ! wait 4000 milliseconds before retransmitting a frame through tokenring 2 llc2 t1-time 4000
Related Commands
Controls the number of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations. Sets the amount of time the Cisco IOS software waits for a final response to a poll frame before resending the poll frame. Sets the amount of time the Cisco IOS software waits for a reply to XID frames before dropping the session. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 tbusy-time interface configuration command to control the amount of time the Cisco IOS software waits until repolling a busy remote station.
llc2 tbusy-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software waits before repolling a busy remote station. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 9600 milliseconds.
Defaults
9600 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
An LLC2 station has the ability to notify other stations that it is temporarily busy, so the other stations will not attempt to send any new information frames. The frames sent to indicate this are called Receiver Not Ready (RNR) frames. Change the value of this parameter only to increase the value for LLC2-speaking stations that have unusually long busy periods before they clear their busy status. Increasing the value will prevent the stations from timing out.
Examples
In the following example, the software will wait up to 12000 milliseconds before attempting to poll a remote station through Token Ring interface 0 to learn the station's status:
! enter a global command, if you have not already interface tokenring 0 ! wait 12000 milliseconds before polling a station through tokenring 0 llc2 tbusy-time 12000
Related Commands
Controls the number of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations. Controls the frequency of polls during periods of idle time (no traffic). Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 tpf-time interface configuration command to set the amount of time the Cisco IOS software waits for a final response to a poll frame before resending the poll frame.
llc2 tpf-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software waits for a final response to a poll frame before resending the poll frame. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 1000 milliseconds.
Defaults
1000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
When sending a command that must receive a response, a poll bit is sent in the frame. This is the receiving station's clue that the sender is expecting some response from it, be it an acknowledgment of information frames or an acknowledgment of more administrative tasks, such as starting and stopping the session. Once a sender gives out the poll bit, it cannot send any other frame with the poll bit set until the receiver replies with a frame containing a final bit set. If the receiver is faulty, it may never return the final bit to the sender. Therefore, the sender could be waiting for a reply that will never come. To avoid this problem, when a poll-bit-set frame is sent, a transmit-poll-frame (TPF) timer is started. If this timer expires, the software assumes that it can send another frame with a poll bit.
Usually, you will not want to change this value. If you do, the value should be larger than the T1 time, set with the llc2 t1-time command. The T1 time determines how long the software waits for receipt of an acknowledgment before sending the next set of frames.
Examples
While you generally will not want to change the transmit-poll-frame time, this example sets the TPF time to 3000 milliseconds. Because the TPF time should be larger than the LLC2 T1 time, this example shows the TPF time as double the LLC2 T1 time.
! enter a global command, if you have not already interface tokenring 0 ! send a poll bit set through tokenring 0 after a 3000 ms delay llc2 tpf-time 3000 ! wait 1500 milliseconds for an acknowledgment before resending I-frames llc2 t1-time 1500
Related Commands
Controls the frequency of polls during periods of idle time (no traffic). Controls the number of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations. Controls the amount of time the Cisco IOS software will wait before resending unacknowledged information frames. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 trej-time interface configuration command to control the amount of time the Cisco IOS software waits for a correct frame after sending a reject command to the remote LLC2 station.
llc2 trej-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software waits for a resend of a rejected frame before sending a reject command to the remote station. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 3200 milliseconds.
Defaults
3200 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
When an LLC2 station sends an information frame, a sequence number is included in the frame. The LLC2 station that receives these frames will expect to receive them in order. If it does not, it can reject a frame and indicate which frame it is expecting to receive instead. Upon sending a reject, the LLC2 station starts a reject timer. If the frames are not received before this timer expires, the session is disconnected.
Examples
In the following example, the software will wait up to 1000 milliseconds to receive a previously rejected frame before resending its reject message to the station that sent the frame:
! enter a global command, if you have not already interface tokenring 0 ! wait 1000 milliseconds before resending a reject message through tokenring 0 llc2 trej-time 1000
Related Commands
Controls the number of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 xid-neg-val-tim interface configuration command to control the frequency of exchange of identification (XID) transmissions by the Cisco IOS software.
llc2 xid-neg-val-time milliseconds
Syntax Description
milliseconds Number of milliseconds after which the software sends XID frames to other LLC2-speaking stations. The minimum is 0 milliseconds and the maximum is 60000 milliseconds. The default is 0 milliseconds.
Defaults
0 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Do not change the llc2 xid-neg-val-time parameter unless requested by your technical support representative.
LLC2-speaking stations can communicate exchange of identification (XID) frames to each other. These frames identify the stations at a higher level than the MAC address and also can contain information about the configuration of the station. These frames are typically sent only during setup and configuration periods when it is deemed that sending them is useful. The greatest frequency at which this information is transferred is controlled by this timer.
Examples
The following example shows how to reset the frequency of XID transmissions to the default of
0 milliseconds:
! enter a global command, if you have not already interface tokenring 0 ! set the frequency of XID transmissions to 0 llc2 xid-neg-val-time 0
Related Commands
Sets the amount of time the Cisco IOS software waits for a reply to XID frames before dropping the session. Displays the LLC2 connections active in the router.
Command
Description
Use the llc2 xid-retry-time interface configuration command to set the amount of time the Cisco IOS software waits for a reply to exchange of identification (XID) frames before dropping the session.
llc2 xid-retry-time milliseconds
Syntax Description
milliseconds Number of milliseconds the software waits for a reply to XID frames before dropping a session. The minimum is 1 millisecond and the maximum is 60000 milliseconds. The default is 60000 milliseconds.
Defaults
60000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This argument was introduced.
Release
Modification
Usage Guidelines
Set this value greater than the value of the T1 time, or the time the software waits for an acknowledgment before dropping the session. T1 time is set with the llc2 t1-time command.
Examples
The following example sets the software to wait up to 60000 milliseconds for a reply to XID frames it sent to remote stations (which resets the value to its default):
! enter a global command, if you have not already interface tokenring 0 ! wait 60000 milliseconds for a reply to XID frames llc2 xid-retry-time 60000
Related Commands
Controls the amount of time the Cisco IOS software will wait before resending unacknowledged information frames. Controls the frequency of XID transmissions by the Cisco IOS software. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc address interface configuration command to assign a set of secondary stations attached to the serial link. Use the no form of this command to remove an assigned secondary station.
sdlc address hexbyte [echo] [switched]
Syntax Description
hexbyte Hexadecimal number (base 16) indicating the address of the serial link. echo (Optional) Treats nonecho and echo SDLC addresses as the same address. switched (Optional) Causes the router to send an XID to an SDLC attached device. When the device answers, then a proxy XID is sent to the peer.
Defaults
No secondary stations are assigned.
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Before using this command, first select the interface on which you want to enable SDLC. Then establish the router as a primary station with the encapsulation sdlc-primary command. Next, assign secondary station addresses to the primary station using the sdlc address command. The addresses are given in hexadecimal (base 16) and are given one per line.
The optional keyword echo is valid only for TG interfaces. When you use the echo keyword, hexbyte is the nonecho SDLC address.
Examples
The following example shows how to configure serial interface 0 to have two SDLC secondary stations attached to it through a modem-sharing device with addresses C1 and C2:
interface serial 0 encapsulation sdlc-primary sdlc address c1 sdlc address c2
Related Commands
Configures the router as the primary SDLC station if you plan to configure the SDLLC media translation feature. Configures the router as a secondary SDLC station if you plan to configure the SDLLC media translation feature. Displays the LLC2 connections active in the router.
Command
Description
Syntax Description
This command has no arguments or keywords.
Command Modes
Interface configuration
Command History
11.0 This command was introduced.
Release
Modification
Usage Guidelines
The sdlc address ff ack-mode command is used to support applications that require local termination of an SDLC connection with address FF. This command should be used only if you use the SDLC address FF as a regular (not a broadcast) address.
Examples
The following example enables local acknowledgment of SDLC address FF:
stun peer-name xxx.xxx.xxx.xxx stun protocol-group 1 sdlc interface serial 1 encapsulation stun stun group 1 stun sdlc-role secondary sdlc address c1 sdlc address ff ack-mode stun route address c1 tcp yyy.yyy.yyy.yyy local-ack stun route address ff tcp yyy.yyy.yyy.yyy local-ack
Related Commands
stun route address tcp Specifies TCP encapsulation and optionally establishes SDLC local acknowledgment (SDLC transport) for STUN.
Command
Description
Use the sdlc dte-timeout interface configuration command to adjust the amount of time a data terminal equipment (DTE) interface waits for the data circuit-terminating equipment (DCE) to assert a Clear To Send (CTS) signal before dropping a Request To Send (RTS).
sdlc dte-timeout unit
Syntax Description
unit Timeout wait interval in microseconds. The valid range is 10 to 64000. Each unit is approximately 5 microseconds. The default is 10 units.
Defaults
10 units (approximately 50 microseconds)
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Use this command on an interface that is in half-duplex mode and that has been configured for DTE.
Examples
The following example sets the amount of time that the DTE waits for the DCE to assert a CTS to 100 units (approximately 500 microseconds):
sdlc dte-timeout 100
Related Commands
half-duplex Specifies half-duplex mode on an SDLC interface or on the FDDI full-duplex, single-mode port adapter and FDDI full-duplex, multimode port adapter on the Cisco 7200 series and Cisco 7500 series routers. half-duplex timer Tunes half-duplex timers.
Command
Description
Use the sdlc frmr-disable interface configuration command to indicate that secondary stations on a particular serial link do not support Frame Rejects (FRMRs) or error indications. Use the no form of this command to specify that the secondary station does support FRMRs.
sdlc frmr-disableSyntax Description
This command has no arguments or keywords.
Defaults
Support of FRMRs or error indications
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
FRMRs are error indications that can be sent to an SDLC station indicating that a protocol error has occurred. Not all SDLC stations support FRMRs. If this command is enabled, when the Cisco IOS software receives an error, it drops the line by sending a disconnect request to the remote station.
Examples
In the following example, the software is set to drop the serial line when it receives a protocol error:
interface serial 0 sdlc frmr-disable
Related Commands
Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc holdq interface configuration command to control the maximum number of packets that can be held in a buffer before being transmitted to a remote SDLC station.
sdlc holdq address queue-size
Syntax Description
address SDLC address for which you are specifying a queue size. queue-size Local send window size. The minimum is 1 packet. No maximum value has been established. The default is 200 packets.
Defaults
200 packets
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
This command is particularly useful with the SDLLC feature that allows an LLC2-speaking SNA station on a Token Ring to communicate with an SDLC-speaking SNA station on a serial link. Frame sizes and window sizes on Token Rings are often much larger than those acceptable for serial links. The fact that serial links are often much slower than Token Rings often makes this problem worse. Therefore, temporary backlogs can exist in periods of high data transfer from the Token Ring station to the serial station. A buffer creates a holding place for backlogged frames awaiting transmission on the serial link. This command is specified for each SDLC address, and therefore, for each SDLC secondary station on the serial link.
Examples
The following example shows how to change the output hold queue length to 30 frames on an SDLC station of address C1 off serial interface 0:
! enter a global command, if you have not already interface serial 0 ! use SDLC encapsulation encapsulation sdlc-primary ! establish address of SDLC station off serial 0 as c1 sdlc address c1 ! change the output hold queue length to 30 frames on the SDLC station sdlc holdq c1 30
Related Commands
Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc k interface configuration command to set the window size in order to control the maximum number of information frames the Cisco IOS software transmits before it must stop transmitting and wait for an acknowledgment from the receiving router.
sdlc k window-size
Syntax Description
window-size Local send window size. The minimum is 1 frame. The maximum is 7 frames, which is the default.
Defaults
7 frames
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
When the Cisco IOS software is communicating with SDLC, it must have a parameter that controls the maximum number of information frames it will send before it must stop sending and wait for an acknowledgment. The k parameter controls this window of acceptable frames. Use this command in conjunction with the sdlc n1 command to create a balance between frame checking and network performance.
Examples
In the following example, the software can send up to five frames before it must receive an acknowledgment:
! enter a global command, if you have not already interface tokenring 0 !send up to 5 frames, then wait for acknowledgment sdlc k 5
Related Commands
Controls the maximum size of an incoming frame. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc line-speed interface configuration command to enable adaptive SDLC T1.
sdlc line-speed rate
Syntax Description
rate Clockrate in bits per second.
Defaults
No default rate
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
This feature is used to calculate the adjusted SDLC T1 value. The adjusted T1 is used to compensate for the delay between the time the system software passes a packet to the microcode, and the time the packet is actually sent out on the line. For a DCE device, this should be equal to the clockrate on the interface. For a DTE device, it should be equal to the clockrate on the DCE device to which the DTE is connected.
Examples
In the following example, the SDLC line-speed rate is set to rate:
sdlc line-speed rate
Related Commands
Determines the number of times that the Cisco IOS software resends a frame before terminating the SDLC session. Controls the amount of time the Cisco IOS software waits for an acknowledgment to a frame or sequence of frames.
Command
Description
Use the sdlc n1 interface configuration command to control the maximum size of an incoming frame.
sdlc n1 bit-count
Syntax Description
bit-count Number indicating bit size. Frames that exceed this size are rejected. The minimum is 1 bit. The maximum is 12000 bits, which is the default.
Defaults
12000 bits
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Use with the sdlc k command to reduce network overhead while continuing to check frame transmission.
Examples
In the following example, the Cisco IOS software rejects frames larger than 10000 bits:
! enter a global command, if you have not already interface tokenring 0 ! reject frames larger than 10000 bits sdlc n1 10000
Related Commands
Sets the window size in order to control the maximum number of information frames the Cisco IOS software sends before it must stop sending and wait for an acknowledgment from the receiving router Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc n2 interface configuration command to determine the number of times that the Cisco IOS software resends a frame before terminating the SDLC session.
sdlc n2 retry-count
Syntax Description
retry-count Number of retry attempts. When this number is exceeded, the SDLC station terminates its session with the other station. The minimum is 1 and the maximum is 255. The default is 20 retries.
Defaults
20 retries
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
Use with the sdlc t1 command to reduce network overhead while continuing to check transmission.
Examples
In the following example, the software is set to drop an SDLC station after five unsuccessful attempts to receive an acknowledgment for a frame:
interface serial 0 sdlc n2 5
Related Commands
Controls the amount of time the Cisco IOS software waits for an acknowledgment to a frame or sequence of frames. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc partner interface configuration command to specify the destination address with which an LLC session is established for the SDLC station. Use the no form of this command to cancel the configuration.
sdlc partner mac-address sdlc-address inbound outbound
Syntax Description
mac-address The 48-bit Media Access Control (MAC) address of the Token Ring host. sdlc-address SDLC address of the serial device that will communicate with the Token Ring host. The valid range is 1 to FE. inbound The inbound option prevents the router from sending proxy XIDs to the remote end station on behalf of the station specified. The remote end station must initiate the connection. When the router is configured for SDLC role secondary, the default is inbound (the router does not send proxy XIDs until it is polled). outbound The outbound parameter causes the router to send proxy XIDs to the partner end station. If the remote end station responds, then (for PU 2.1 local devices) a NULL XID is sent on the SDLC line. The default behavior for sdlc role primary is outbound, and sdlc role secondary is inbound.
Defaults
No partner is defined.
Command Modes
Interface configuration
Command History
11.0 This command was introduced. 11.2 This command was updated to include the inbound and outbound parameters.
Release
Modification
Usage Guidelines
The inbound keyword prevents unwanted messages on the host operator console from inbound XID's to inactive VTAM Switched Major Nodes. It directs SDLC to not send Test or XID frames to the host, FEP, or 3172 even after the connection to a downstream PU2 is complete. The inbound keyword is required for System88 support. The outbound keyword TBD.
Examples
The following example establishes the correspondence between an SDLC and QLLC connection:
sdlc partner 1000.5aed.1f53 d2 inbound outbound
Related Commands
Configures an SDLC interface. sdlc dlsw Attaches SDLC addresses to DLSw+. Configures a MAC address for the serial interface.
Command
Description
Use the sdlc poll-limit-value interface configuration command to control how many times a single secondary station can be polled for input before the next station must be polled. Use the no form of this command to retrieve the default value.
sdlc poll-limit-value count
Syntax Description
count Number of times the Cisco IOS software can poll one secondary station before proceeding to the next station. The minimum is 1 time, which is the default. The maximum is 10 times.
Defaults
1 time
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
As is typical for the primary station of an SDLC connection, if a secondary station sends its full possible window of input to the primary router or access server, the Cisco IOS software immediately will re-poll the same secondary for more data in an attempt to capture the complete transaction at one time. The sdlc poll-limit-value command indicates how many times this can happen before the next station in the poll loop must be polled.
Increasing the value allows for smoother transaction processing but can delay polling of other stations or giving output to other stations.
Examples
The following example specifies that the router can be polled two times before the next station in the poll list must be polled:
! enter a global command, if you have not already interface serial 4 no ip address ! use stun encapsulation encapsulation stun ! establish stun group 4 on interface serial 4 stun group 4 stun sdlc-role primary ! poll the router up to two times before polling the next station sdlc poll-limit-value 2
Related Commands
Controls how long the Cisco IOS software pauses between sending each poll frame to secondary stations on a single serial interface. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc poll-pause-timer interface configuration command to control how long the Cisco IOS software pauses between sending each poll frame to secondary stations on a single serial interface. Use the no form of this command to retrieve the default value.
sdlc poll-pause-timer milliseconds
Syntax Description
milliseconds Number of milliseconds that the software waits before sending the poll frame to a single serial interface. This is a number in the range 1 to 10000. The default is 10 milliseconds.
Defaults
10 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
As is typical for the primary station of an SDLC connection, the software generates polls periodically to each of the secondary stations to solicit their input. After polling each station on a single serial interface, the software will pause before beginning to poll the next station.
Because the secondaries cannot transmit data until they are polled, increasing this timer can increase response time to the users. However, making this parameter too small can flood the serial link with unneeded polls and require the secondary stations to spend wasted CPU time processing them.
Examples
In the following example, the software pauses 2000 milliseconds before sending a series of poll frames through serial interface 4:
! enter a global command, if you have not already interface serial 4 no ip address ! use STUN encapsulation encapsulation stun ! establish stun group 4 on interface serial 4 stun group 4 ! stun sdlc-role primary ! wait 2000 milliseconds before sending each series of poll frames sdlc poll-pause-timer 2000
Related Commands
Controls how many times a single secondary station can be polled for input before the next station must be polled. Displays the LLC2 connections active in the router.
Command
Description
Syntax Description
milliseconds Number of milliseconds the software will wait for a poll from the primary station before timing out the connection to the primary station. The minimum is 10 milliseconds and the maximum is 64000 milliseconds. The default is 10000 milliseconds.
Defaults
10000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
This command can be used on an interface that has been configured as a secondary node, but is not to be used on an interface that has been configured as a primary node.
In a locally acknowledged multidrop environment, the polls the primary node sends to the router can be delayed because the primary node is busy polling other secondary nodes. In such situations, this command can be used to extend the timeout, thus reducing the likelihood the Cisco IOS software times out the connection to the primary node.
Examples
The following example specifies that the local software will wait an interval of 63000 milliseconds for a poll from a primary station before timing out:
! sample stun peer-name global command stun peer-name 150.136.134.86 ! sample protocol-group command stun protocol-group 4 sdlc ! interface serial 0 ! sample ip address command no ip address ! sample encapsulation stun command encapsulation stun ! place interface serial0 in previously defined STUN group 4 stun group 4 ! must enter the next command to use the sdlc poll-wait-timeout command stun sdlc-role secondary ! set timeout period for polls from primary station to 63000 milliseconds. sdlc poll-wait-timeout 63000 ! list the addresses of the sdlc stations on the link sdlc address C1 sdlc address C2 ! provide stun route command stun route address C2 tcp 150.136.134.58 stun route address C1 tcp 150.136.134.58
Related Commands
Controls how many times a single secondary station can be polled for input before the next station must be polled. Controls how long the Cisco IOS software pauses between sending each poll frame to secondary stations on a single serial interface.
Command
Description
To establish correspondence between an SDLC and QLLC connection, use the sdlc qllc-prtnr interface configuration command.
sdlc qllc-prtnr virtual-mac-address sdlc-address
Syntax Description
virtual-mac-address The virtual Media Access Control (MAC) address in the form h.h.h. sdlc-address SDLC address in hexadecimal. The valid range is 1 to FE.
Defaults
No correspondence is defined.
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Examples
The following example establishes the correspondence between an SDLC and QLLC connection:
sdlc qllc-prtnr 4000.0122.0001 c1
Related Commands
Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc role interface configuration command to establish the router to be either a primary or secondary SDLC station. Use the no form of this command to cancel the designation.
sdlc role {none | primary | secondary | prim-xid-poll}
Syntax Description
none Establishes the router as either a primary or secondary station, depending on the end stations. primary Establishes the router as a primary station. secondary Establishes the router as a secondary station. prim-xid-poll Establishes the router as a primary station when the end station is configured as a secondary NT2.1.
Defaults
No default role is assigned.
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
If the role is none, the router can be either primary or secondary, depending on the end stations. The SDLC end station must be configured as negotiable or primary NT2.1. When the end stations are configured as Physical Unit type 2 (PU 2), you can set the role of the interface to primary or secondary. When the end station is configured as secondary NT2.1, you must set the role of the interface to prim-xid-poll.
To configure an SDLC multidrop line (downstream), configure the SDLC role as follows:
Examples
The following example configures the router as a primary SDLC station:
interface serial 2/6 no ip address encapsulation sdlc fras map sdlc c1 serial 2/0 frame-relay 32 4 4 sdlc role primary sdlc address c1 sdlc xid c1 01700001
Related Commands
Configures an SDLC interface.
Command
Description
Use the sdlc sdlc-largest-frame interface configuration command to indicate the largest information frame (I-frame) size that can be sent or received by the designated SDLC station. Use the no form of this command to return to the default value.
sdlc sdlc-largest-frame address size
Syntax Description
address Address of the SDLC station that will communicate with the router. size Largest frame size that can be sent or received. The default is 265 bytes.
Defaults
The default largest I-frame is 265 bytes.
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Examples
In the following example, the Cisco IOS software can send or receive a frame as large as 265 bytes (the default) from the SDLC station at address C6. Any frames larger will be fragmented by the software.
interface serial 4 sdlc sdlc-largest-frame c6 265
To enable an interface configured as a primary SDLC station to operate in two-way simultaneous mode, use the sdlc simultaneous interface configuration command.
sdlc simultaneous [full-datamode | half-datamode]
Syntax Description
full-datamode (Optional) Enables the primary station to send data to and receive data from the polled secondary station. half-datamode (Optional) Prohibits the primary station from sending data to the polled secondary station.
Defaults
Two-way simultaneous mode is disabled.
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
By default, the SDLC driver supports alternative mode. This means that in a multidrop environment, the primary station cannot send data to another secondary station until it receives a response (F bit) from the secondary station with which it is currently communicating.
In contrast, two-way simultaneous mode enables the interface configured as a primary SDLC station to send data to a second secondary station, even when it is receiving data from another secondary station. This capability improves utilization of a full-duplex serial line.
Examples
The following example enables all primary stations to send and receive data at the same time:
sdlc simultaneous full-datamode
The following example enables all secondary stations to send or receive data at the same time:
sdlc simultaneous half-datamode
Related Commands
Configures the router as the primary SDLC station if you plan to configure the SDLLC media translation feature. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc slow-poll interface configuration command to enable the slow-poll capability of the router as a primary SDLC station. Use the no form of this command to disable slow-poll capability.
sdlc slow-poll seconds
Syntax Description
seconds Amount of time in seconds.
Defaults
10 seconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
You can use this command to improve the performance of a multidropped SDLC configuration when one or more of the secondary stations are inactive.
When slow-poll is enabled, if the router acting as a primary station detects that a secondary SDLC station is not responding, it polls that secondary SDLC station less frequently. The router spends less time waiting for the inactive secondary station to respond, thereby minimizing the performance degradation on the active secondary SDLC stations on the multidropped line.
Examples
The following example enables the slow-poll capability:
interface serial 0 sdlc slow-poll
Related Commands
Controls how many times a single secondary station can be polled for input before the next station must be polled. Controls how long the Cisco IOS software pauses between sending each poll frame to secondary stations on a single serial interface. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc t1 interface configuration command to control the amount of time the Cisco IOS software waits for an acknowledgment to a frame or sequence of frames.
sdlc t1 milliseconds
Syntax Description
milliseconds Number of milliseconds that the software waits. The minimum is 1 millisecond and the maximum is 64000 milliseconds. The default is 3000 milliseconds.
Defaults
3000 milliseconds
Command Modes
Interface configuration
Command History
10.0 This command was introduced.
Release
Modification
Usage Guidelines
When an SDLC station sends a frame, it waits for an acknowledgment from the receiver that the frame has been received. The sending station cannot wait indefinitely for a response. When the frame is sent, a timer is started. To be consistent with the original specification of SDLC, this timer is called the T1 timer and is controlled by this parameter. If this timer reaches its limit before the acknowledgment is received, the software will try again and resend the frame.
Examples
In the following example, the software waits up to 4000 milliseconds for a reply to a frame or sequence of frames:
! enter a global command, if you have not already interface tokenring 0 sdlc t1 4000
Related Commands
Determines the number of times that the Cisco IOS software resends a frame before terminating the SDLC session. Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc test serial EXEC command to determine the status of end stations. Use the sdlc test serial command with the stop keyword to halt the sending of the test frames.
sdlc test serial number address [iterations | continuous | stop | string string]
Syntax Description
serial number Serial interface on which the test frame is to be sent out. address SDLC address (in hexadecimal) of the end station to receive the test frame. iterations (Optional) Number of test frames to be sent. The valid range is 1 to 25 frames. The default is 10 frames. continuous (Optional) Sends frames continuously until the sdlc test serial command is issued with the stop keyword. stop (Optional) Halts the sending of test frames. string string (Optional) Specifies a string of characters as data within the test frame. If this option is not specified, the default test string is ABCDEFGHIJKLMNOPQRSTUVWXYZ.
Defaults
The sdlc test serial command is not active.
The default test string is "ABCDEFGHIJKLMNOPQRSTUVWXYZ."
Command Modes
EXEC
Command History
11.2 This command was introduced.
Release
Modification
Usage Guidelines
The command will pre-check for correct interface and SDLC address. The results of the test frames sent can be viewed after the frames have been sent or an sdlc test serial command with the stop keyword has been issued.
Examples
The following are variations of the sdlc test serial command, followed by the response for each:
Router# sdlc test serial 0 c1 SDLC Test for address C1 completed Frames sent=10 Frames received=10 Router# sdlc test serial 0 c1 255 SDLC Test for address C1 completed Frames sent=255 Frames received=255 Router# sdlc test serial 0 C1 stop SDLC Test for address C1 completed Frames sent=44 Frames received=44 Router# sdlc test serial 0 c1 string HeyMrPUareyouthere SDLC Test for address C1 completed Frames sent=10 Frames received=10
Related Commands
Displays the LLC2 connections active in the router.
Command
Description
Use the sdlc vmac interface configuration command to configure a MAC address for the serial interface. Use the no form of this command to disable the configuration.
sdlc vmac mac-address
Syntax Description
mac-address 48-bit MAC address of the Token Ring host.
Defaults
Disabled
Command Modes
Interface configuration
Command History
11.0 This command was introduced.
Release
Modification
Usage Guidelines
This command must be configured if you plan to configure DLSw+. The last byte of the address must be 00.
Examples
The following example specifies a MAC address for the serial interface:
sdlc vmac 1234.3174.0000
Related Commands
Configures an SDLC interface. sdlc dlsw Attaches SDLC addresses to DLSw+.
Command
Description
Use the sdlc xid interface configuration command to specify an exchange ID (XID) value appropriate for the designated SDLC station associated with this serial interface. Use the no form of this command to disable XID processing for this address.
sdlc xid address xid
Syntax Description
address Address of the SDLC station associated with this interface. xid XID the Cisco IOS software will use to respond to XID requests the router receives. This value must be 4 bytes (8 digits) in length and is specified with hexadecimal digits.
Defaults
Disabled
Command Modes
Interface configuration
Command History
10.3 This command was introduced.
Release
Modification
Usage Guidelines
XID requests and responses are usually exchanged before sessions are started. Be sure that the XID value configured in the Cisco IOS software matches the IDBLK and IDNUM parameters configured on the host. The XID response to an XID request will contain the information you configured in the sdlc xid command. The host will check the XID response it receives with the IDBLK and IDNUM parameters (that are configured in the VTAM). If they match, the host will initiate a session with the router. If they do not match, the host will not initiate a session.
Examples
The following example specifies an XID value of 01720002 at address C2:
interface serial 0 sdlc xid c2 01720002
Related Commands
Configures an SDLC interface.
Command
Description
Use the show llc2 privileged EXEC command to display the LLC2 connections active in the router.
show llc2Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
10.0 This command was introduced.
Release
Modification
Examples
The following is sample output from the show llc2 command:
Router# show llc2 TokenRing0 DTE=1000.5A59.04F9,400022224444 SAP=04/04, State=NORMAL V(S)=5, V(R)=5, Last N(R)=5, Local window=7, Remote Window=127 ack-max=3, n2=8, Next timer in 7768 xid-retry timer 0/60000 ack timer 0/1000 p timer 0/1000 idle timer 7768/10000 rej timer 0/3200 busy timer 0/9600 ack-delay timer 0/3200 CMNS Connections to: Address 1000.5A59.04F9 via Ethernet2 Protocol is up Interface type X25-DCE RESTARTS 0/1 Timers: T10 1 T11 1 T12 1 T13 1
The display includes a CMNS addendum, indicating LLC2 is running with CMNS. When LLC2 is not running with CMNS, the show llc2 command does not display a CMNS addendum.
Table 37 describes significant fields shown in the display.
| Field | Description |
|---|---|
TokenRing0 | Name of interface on which the session is established. |
DTE=1000.5A59.04F9, 400022224444 | Address of the station to which the router is talking on this session. (The address is the MAC address of the interface on which the connection is established, except when Local Acknowledgment or SDLLC is used, in which case the address used by the Cisco IOS software is shown as in this example, following the DTE address and separated by a comma.) |
SAP=04/04 | Other station's and the router's (remote/local) service access point (SAP) for this connection. The SAP is analogous to a "port number" on the router and allows for multiple sessions between the same two stations. |
State=NORMAL | Current state of the LLC2 session. The possible values are:
|
V(S)=5 | Sequence number of the next information frame this station will send. |
V(R)=5 | Sequence number of the next information frame this station expects to receive from the other station. |
Last N (R)=5 | Last sequence number of this station's transmitted frames acknowledged by the remote station. |
Local Window=7 | Number of frames this station may send before requiring an acknowledgment from the remote station. |
Remote Window=127 | Number of frames this station can accept from the remote. |
ack-max=3, n2=8 | Value of these parameters, as given in the previous configuration section. |
Next timer in 7768 | Number of milliseconds before the next timer, for any reason, goes off. |
xid-retry timer 0/60000.... | Series of timer values in the form of next-time/time-between, where "next-time" is the next time, in milliseconds, that the timer will wake, and "time-between" is the time, in milliseconds, between each timer wakeup. A "next-time" of zero indicates that the given timer is not enabled, and will never wake. |
CMNS Connections to: | List of values that affect the interface if CMNS is enabled. |
Address 1000.5A59.04F9 via Ethernet2 | MAC address of remote station. |
Protocol is up | Up indicates the LLC2 and X.25 protocols are in a state where incoming and outgoing Call Requests can be made on this LLC2 connection. |
Interface type X25-DCE | One of X25-DCE, X25-DTE, or X25-DXE (both DTE and DCE). |
RESTARTS 0/1 | Restarts sent/received on this LLC2 connection. |
Timers: | T10, T11, T12, T13 (or T20, T21, T22, T23 for DTE); these are Request packet timers. These are similar in function to X.25 parameters of the same name. |
Related Commands
Sets the amount of time the Cisco IOS software waits for an acknowledgment before sending the next set of information frames. Controls the maximum amount of information frames the Cisco IOS software can receive before it must send an acknowledgment. Controls the frequency of polls during periods of idle time (no traffic). Controls the maximum number of information frames the Cisco IOS software sends before it waits for an acknowledgment. Controls the number of times the Cisco IOS software retries sending unacknowledged frames or repolls remote busy stations. Controls the amount of time the Cisco IOS software will wait before resending unacknowledged information frames. Controls the amount of time the Cisco IOS software waits until repolling a busy remote station. Sets the amount of time the Cisco IOS software waits for a final response to a poll frame before resending the poll frame. Controls the amount of time the Cisco IOS software waits for a correct frame after sending a reject command to the remote LLC2 station. Controls the frequency of XID transmissions by the Cisco IOS software. Sets the amount of time the Cisco IOS software waits for a reply to XID frames before dropping the session.
Command
Description
Posted: Wed Aug 23 07:13:48 PDT 2000
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