This document describes the Nx Networks implementation of Frame Relay and how to configure it. It includes the following sections:
Frame Relay Overview
Frame Relay Manager (FRMGR)
Frame Relay LAN Emulation (FRLANE)
Frame Relay Virtual Circuit (FRVC)
Choosing Between FRLANE and FRVC
Frame Relay over ISDN
Displaying the Frame Relay Prompts
Configuring Frame Relay
FRMGR Commands
FRLANE Commands
FRVC Commands
Frame Relay Overview
Frame Relay (FR) lets you connect multiple LANs to a single high-speed WAN link using point-to-point virtual circuits. A virtual circuit is a logical connection between two sites. The FR network provides a number of virtual circuits that connect stations attached to the same Frame Relay network.
A Frame Relay network consists of the FR backbone, made up of FR switches, that provides the service. Typically, a public Frame Relay supplier offers the Frame Relay service. The router acts as the device that connects your LANs to the Frame Relay WAN.
Terminology
This document uses the following terminology.
Frame Relay Services
Like other Nx Networks WAN implementations, Frame Relay consists of a physical device and logical interfaces. Logical interfaces run over the physical device, and you can have multiple logical interfaces running over one physical device. In addition, multiple Frame Relay VCs can run over each logical interface.
The Frame Relay software provides a set of services made up of the following:
Frame Relay Manager (FRMGR), which manages the physical Frame Relay device, handles the connection to the Frame Relay switch, manages PVCs, and allows other Frame Relay services, FRLANE and FRVC, to run on the Frame Relay device.
Frame Relay LAN Emulation (FRLANE), which acts as a logical interface running over the Frame Relay device. An FRLANE interface looks like an Ethernet or Token Ring interface to protocols. Each FRLANE interface can have many PVCs.
Frame Relay Virtual Circuit (FRVC), which also acts as a logical interface running over the Frame Relay device. Each FRVC interface uses a single PVC.
Figure 1 Frame Relay Device With Two FRLANE Interfaces and One FRVC Interface
Frame Relay Features
Frame Relay provides the following features:
High throughput and low delay. Using the core aspects (error detection, addressing, and synchronization) of the Link Access Protocol, D-channel (LAPD) datalink protocol, FR eliminates all network layer (Layer 3) processing. By using only the core aspects, FR reduces the delay of processing each frame.
LAN Emulation. Using FRLANE, you can group many circuits onto one interface. FRLANE features include static or dynamic address mapping, multicast emulation, and protocol broadcast.
Single Virtual Circuit Mode. Using FRVC, the VC acts as a point-to-point connection to protocols that run over the VC.
PPP over FRVC. Frame Relay Virtual Circuits can send PPP traffic over the circuit using PPP over Frame Relay encapsulation specified in RFC 1973. Using this feature along with PPP data compression gives you a method of compressing data sent over the circuit.
Network management. As your network requires, Frame Relay can operate with or without a Local Management Interface (LMI).
Circuit access and control. As the router dynamically learns about nonconfigured circuits (orphan circuits), you can control access to those new circuits.
Congestion detection and control. Upon receiving Backward Explicit Congestion Notification (BECN), the router initiates a controlled slowdown of traffic, thereby avoiding a complete FR network shutdown.
1490 Encapsulation. The router encapsulates protocol packets as specified in RFC 1490.
Multiplexing Virtual Circuits. Frame Relay can pass multiple protocols over one circuit. OpenROUTE software supports IP, IPX, AppleTalk, and bridging.
Statistics. Frame Relay monitoring commands provide current statistics on circuits and LMI exchanges.
How Frame Relay Works
Frame Relay routes traffic based on a Data Link Connection Identifier (DLCI). The DLCI allows devices to identify a frame as being from a particular virtual circuit. The DLCI enables multiplexing of several virtual circuits over one physical link.
For example, in Figure 2, a packet destined to go from router B to router C has a DLCI of 19; however, a packet destined to go from router C to router B has a DLCI of 16.
Figure 2 DLCIs in Frame Relay Network
You can configure static circuits and/or use dynamic circuits that FR management learns about from the FR network.
A Frame Relay network has the following characteristics:
Transports frames transparently. The network can modify only the DLCI, congestion bits, and frame check sequence. High-level Data Link Control (HDLC) flags and zero bit insertion provide frame delimiting, alignment, and transparency.
Detects transmission, format, and operational errors (frames with an unknown DLCI).
Preserves the ordering of frame transfer on individual VCs.
Does not acknowledge or retransmit frames.
| Field | Description |
|---|---|
| HDLC Flags | Located in the first and last octet, HDLC flags indicate the beginning and end of the frame. |
| Data Link Connection Identifier (DLCI) | This 10-bit routing ID resides in bits 3-8 of octet 2 and bits 5-8 of octet 3. The DLCI is the MAC address of the circuit. |
| Command/Response (C/R) | This is LAPD-specific, and this version of FR does not use C/R. |
| Extended Address (EA) | This version of FR does not support extended addressing. |
| Forward Explicit Congestion Notification (FECN) | When this bit is set to 1, the FR backbone network notifies the user receiving the frames that congestion is occurring in the direction the frame is being sent. |
| Backward Explicit Congestion Notification (BECN) | When this bit is set to 1, the FR backbone network notifies the device sending the frames that congestion is occurring in the opposite direction. When the router receives a BECN, it begins a throttle down. |
| Discard Eligibility (DE) | The network may discard transmitted data exceeding the Committed Information Rate (CIR) on a PVC. The network end node sets the DE bit to indicate discard eligibility. This version of FR does not set the DE bit. |
| User Data | This field contains the protocol packet being transmitted. It can contain a maximum of 8189 octets; however, the frame check sequence (FCS) can effectively detect errors only on a maximum of 4096 octets of data. |
| Frame Check Sequence (FCS) | This field is the standard 16-bit Cyclic Redundancy Check (CRC) that HDLC and LAPD frames use. FCS detects bit errors occurring in the bits of the frame between the opening flag and FCS. |
Frame Relay Manager (FRMGR)
The FRMGR configuration applies to all logical interfaces that run over the physical Frame Relay device. FRMGR handles the following Frame Relay management tasks, which are described in the next sections.
This Frame Relay implementation supports the Local Management Interface (LMI) entities LMI Revision 1, ANSI Annex D, and CCITT Annex A. LMI notifies FRMGR of the following:
PVC status, including whether a PVC is active or inactive or has been deleted. Through PVC status, FRMGR learns about orphan circuits. See Full Status Report.
The integrity of the physical link between the end station and the Frame Relay switch. See Link Integrity Verification Report.
Network congestion using FECN and BECN bit settings.
PVC Status
FRMGR uses LMI to interact with the Frame Relay switch to find out the status of PVCs. PVCs are either active or inactive. An active circuit has a completed connection to an end system. An inactive circuit does not have a completed connection to an end system because either an end system or an FR switch is offline.
The Frame Relay device cannot send or receive data until an LMI full status message reports the PVC as active.
For example, in Figure 4 router B has a configured PVC to router C. Router B is successfully interacting with FR management through FR switch B. Because either another FR switch is down or the end system is down, the end-to-end PVC connection is not established. Router B receives an inactive status for that PVC.
Figure 4 DLCIs in Frame Relay Network
Orphan Circuits
An orphan circuit is a virtual circuit that is not configured,
but that FRMGR dynamically learns through LMI. For example, in Figure
5 router B has a configured PVC to router C, but none to router A. Router
A configures a PVC to router B. Router B then learns about the PVC to router A
and classifies it as an orphan.
The Inverse ARP protocol for Frame Relay maps the orphan circuit DLCI (a hardware address) to a protocol address. To do this, the router sends an Inverse ARP request over the orphan circuit to the end node router (Router A in Figure 5), which returns a protocol address.
The router treats orphan circuits the same as configured circuits, except that you can enable or disable them. Enabling orphan circuits allows the router to forward packets over circuits you did not configure. Disabling orphan circuits adds a measure of security to your network by preventing unauthorized entry into your network from a nonconfigured circuit.
Management Status Reporting
Upon request, LMI provides two types of status reports, a full status report and a link integrity verification report. The next sections describe these reports. FR sends status enquiries and responses over DLCI 0 for ANSI Annex D and CCITT or DLCI 1023 for LMI Rev 1.
Enter list lmi at the FRMGR <WAN> prompt to see current status information.
Full Status Report
When FRMGR requires a full status report, it sends a status enquiry to management requesting a full status report. LMI responds with a full status report consisting of the link integrity verification element and the status of all PVCs on the device. (The next section describes the link integrity verification element.)
The PVC status contains the following information: the local DLCI number for the PVC; the state of the PVC (active or inactive); and whether the PVC is new or an existing PVC that management already knows about.
Note: The number of PVCs that LMI supplies to the FR device is restricted by the network frame size and the amount of individual PVC information elements that can fit into a full status report. For example, 202 is the maximum number of PVCs for a network with a 1K frame size.
The send sequence number is the current send sequence number of the message originator. The receiver looks at this number and compares it to the last send sequence number to verify that the number is incrementally correct.
The receive sequence number is the last send sequence number that the originator sent over the interface. It is the receiver's responsibility to place a copy of the send sequence number into the receive sequence number field. This way the originator ensures that the receiver receives and interprets the frames correctly.
If an end station fails to participate in this polling process, management's full status report notifies all remote end stations with logically attached PVCs.
Managing Errors
You can set a threshold for the number of management events that can contain errors during an event window. If the number of errors exceed this threshold, Frame Relay disconnects the link.
The n2-parameter sets the error threshold. The n3-parameter sets the event window. For example:
This sets an error threshold of 3 (n2 = 3) and a window size of 4 (n3 = 4), which causes the software to check four management events to determine if any are in error. If the number of events in error equals three (the n2 parameter) or more, the Frame Relay device considers the network to be Down and resets.FRMGR Config <WAN> set n2-parameter
Parameter N2 [3]?
FRMGR Config <WAN> set n3-parameter
Parameter N3 [4]?
For the Frame Relay device to consider the network to be Up, the number of events in error within the window must be less than n2 prior to any change in status.
Defining Data Rates
Your Frame Relay service provider can tell you the correct
value for each data rate. You can use the defaults or define these rates with
the add permanent-virtual-circuit FRMGR command.
The router does not negotiate these rates with the Frame Relay switch.
Committed Information Rate (CIR)
CIR is the data rate that the FR service provider commits to support for both PVCs and orphan circuits under normal, uncongested conditions. The CIR is a portion of the total throughput for the physical link between 300 bits per second (bps) and 1.54 Megabits per second (Mbps). The most common CIR, and the default CIR, is 64 Kilobits per second (Kbps).
Orphan Circuit CIR
The router assigns orphan circuits a CIR of 64 Kbps. If you rely on an orphan circuit to route important data, you should add a PVC in place of the orphan. Doing so lets you assign a CIR that the network commits to support.
Committed Burst (Bc) Size
Bc is the maximum amount of data in bits that the network commits to deliver during a calculated time (Tc) interval. To calculate the Tc, divide the Bc by the CIR.
For example, if a VC's CIR is 9600 bps, and the Bc is 14,400 bits, the Tc is 1.5 seconds (14,400/9600 = 1.5 seconds). This allows the VC to transmit a maximum of 14,400 bits in 1.5 seconds.Bc/CIR = Tc
The Bc is important because of its relationship to the maximum frame size. If the maximum frame size in bits is greater than the Bc, the network may discard frames whose size exceeds the Bc. Therefore, make sure the Bc is greater than or equal to the maximum frame size.
Excess Burst (Be) Size
Be is the maximum amount of uncommitted data the router can transmit on a VC in excess of the Bc during the time interval Tc (Bc/CIR=Tc).
The network delivers this excess data with a lower probability of success than committed burst size data. Set the Be greater than zero only if you are willing to accept the risk of discarded data and its effect on higher-layer protocol performance.
Minimum and Maximum Information Rates (IR)
The minimum IR is the minimum amount of data the router
sends over a VC in time interval Tc (Tc=Bc/CIR) during periods of
network congestion. Set the minimum IR using the set
ir-adjustment command.
The maximum IR is the maximum amount of data the router sends.
You do not set the maximum IR; the router calculates the maximum IR using the CIR, Bc, and Be as follows:
(Bc + Be) / Tc = maximum IR
To avoid impulse loading of the network, the router initially sets the VIR to CIR when the network starts up.
The VIR can actually exceed the maximum IR in one case. If the length of a frame in bits is greater than the maximum IR, Frame Relay transmits the frame anyway.
Responding to Circuit Congestion
When circuit congestion occurs, the network must drop packets and/or shut down. In response to circuit congestion, the router implements a throttle down, which is a stepwise slowing of packet transmission to the configured minimum IR. Throttle down occurs during the following conditions:
Circuit congestion is occurring.
The router is the sender of frames.
CIR monitoring or congestion monitoring is enabled.
CIR Monitoring
CIR monitoring prevents the information rate (IR) of each VC from exceeding its maximum IR.
CIR monitoring is disabled by default. To enable it, enter the enable cir-monitor command. CIR monitoring, when enabled, overrides congestion monitoring.
Congestion Monitoring
Congestion monitoring allows the VIR to vary in response
to network congestion. The VIR assumes values between the minimum IR and a maximum
of line speed. Congestion monitoring is enabled by default. You can disable it
with the disable congestion-monitor command.
CIR monitoring, if enabled, overrides congestion monitoring. If both CIR monitoring and congestion monitoring are disabled, the VIR for each VC on the device is set to the line speed and does not change in response to network congestion.
Congestion Notification and Avoidance
Frame Relay frames contain two bits that notify the device sending or receiving frames if there is congestion on the network. The two bits are
Forward Explicit Congestion Notification (FECN), which notifies devices receiving frames that congestion is occurring in the direction the frame is being sent.
Backward Explicit Congestion Notification (BECN), which notifies devices sending frames that congestion is occurring in the opposite direction.
Use the set ir-adjustment command to set the minimum IR and the percentages for increasing and decreasing the IR in response to network congestion.
Figure 6 shows a congestion condition at switch B. Management notifies the downstream node (switch C) and the end station (router) that congestion is occurring by setting the FECN bit on all outgoing frames. Management must also notify switch A and the other end station that congestion is occurring by setting the BECN bit.
Figure 6 Congestion Notification and Throttle Down
Note: If multiple VCs are configured between two end stations when congestion occurs, the router may use a second VC to send data until the congestion on the first VC clears.
You can set up multiple FRLANE interfaces on each physical Frame Relay device. Each FRLANE interface can have a different protocol address and can belong to a different network. Routing protocols, such as RIP or OSPF, treat each FRLANE interface as a separate network. These features let you set up FRLANE interfaces that represent your network address structure, giving you better control of your network.
Address Mapping
When FRLANE receives a packet, it knows which virtual circuit to send the packet to by mapping the packet's protocol address to a DLCI.
You can either statically map protocol addresses to PVCs, or Frame Relay can learn them dynamically through the Inverse Address Resolution Protocol (ARP). Static address mapping can reduce broadcast traffic. In either case, Frame Relay performs this mapping by comparing the packet's protocol address to the entries in its ARP cache. If the ARP cache
contains the DLCI that matches the protocol address, FR encapsulates that packet into a frame and sends the frame over the specified circuit.
does not contain a match, FR sends an ARP request over all of its configured PVCs. When the appropriate end point sends an ARP response, FR adds the local DLCI of the circuit that received the ARP response to the ARP cache.
Protocol Broadcast
Protocol broadcast allows protocols such as RIP to function
over the FRLANE interface. The multicast parameter must be enabled for protocol
broadcast to function properly. You can turn this feature on or off using the
enable protocol-broadcast and disable
protocol-broadcast FRLANE commands.
LAN Emulation Groups
LAN emulation groups allow an FRLANE interface to use only the VCs you configured for that FRLANE interface and not circuits that it learns about from FRMGR.
You may want to enable LAN emulation groups in either of the following situations:
If you have VCs on an FRLANE interface and want to prevent other FRLANE interfaces from using those VCs. Otherwise, if you have multiple FRLANE interfaces on one Frame Relay device, the first FRLANE to send a unicast frame on a circuit gets exclusive use of the circuit.
If you have a number of FRLANE interfaces on one device. Without LAN emulation groups, all FRLANE interfaces could send broadcasts to the FRMGR, and FRMGR could broadcast multiple copies of the same frame over the Frame Relay network.
Frame Relay Virtual Circuit (FRVC)
FRVC interfaces use a point-to-point connection over a single VC. You can have multiple FRVC interfaces on each physical Frame Relay device. Each FRVC has one VC. You can use FRVC interfaces over orphan circuits.
The router encapsulates IP, IPX, AppleTalk, and bridging packets using RFC 1490 encapsulation and then routes them over the FRVC interface.
You can also send PPP data over an FRVC. Using this feature along with PPP data compression gives you a method of sending compressed data over an FRVC. The router uses PPP over Frame Relay encapsulation specified in RFC 1973.
With FRVC, the VC acts as a point-to-point connection to protocols that run over the VC. For example, if you are using IP, you can run RIP or use static routes over the VC. You can also assign a different IP address to each FRVC interface, which allows you to set up separate IP filters for each FRVC.
FRVC responds to Inverse ARP requests that it receives.
Choosing Between FRLANE and FRVC
Consider the following when deciding whether to use FRLANE or FRVC.
FRVC
FRVC is the default configuration for Frame Relay devices. FRVC uses one VC for each FRVC interface, and it is simpler to set up than FRLANE.
FRVC causes a VC to act as a point-to-point connection to protocols. If you use FRVC, you can
assign different IP addresses to each VC
use RIP or static routes over the FRVC interface
enable PPP over FRVC, which lets you send compressed PPP data over your Frame Relay connection
You can use FRLANE to group many circuits on one Frame Relay device, which lets you use only one IP address for all circuits in a group.
Each FRLANE interface can have a different IP address and can belong to a different network. Therefore, you can set up FRLANE virtual interfaces to represent your network address structure, giving you better control of your network.
Frame Relay over ISDN
Figure 7 shows how you
can use ISDN to connect to a Frame Relay switch.
Figure 7 Frame Relay Over ISDN Configuration
Because of the costs involved, Frame Relay over ISDN is usually not suitable for continuous connections.
Keep the following in mind if you are using Frame Relay over IDSN:
FRMGR unconditionally calls the Frame Relay switch when the router restarts even if you have dial-on-demand enabled. It does so because Frame Relay needs the status of PVCs.
You can set up FRMGR to disconnect from the Frame Relay switch if no upper-layer protocol requests a connection. (Use the set idle-timeout FRMGR configuration command.)
You can also set up FRMGR to periodically reconnect to the Frame Relay switch to update PVC status. (Use the set redial-timer FRMGR configuration command.)
Displaying the FRMGR Prompts
Note:
The FRMGR configuration applies to all interfaces on a physical Frame Relay device. If you have multiple interfaces on one device, it does not matter which Circuit Config <NET-#> prompt for the device you use to get to the FRMGR prompt.
To display the FR Manager configuration prompt (FRMGR Config <WAN>),
Config> prompt, enter list interfaces to see a list of interfaces configured on the router.
Config>set data-link frame-relay
Interface Number [0]? 1
Config>network
What is the network number [0]? 1
Circuit Configuration
Circuit Config <NET-1>
Circuit Config <NET-1> frmgr
Frame Relay Manager Configuration
FRMGR Config <WAN>
FRMGR <WAN>), Monitor> prompt, enter list interfaces to see a list of interfaces configured on the router. Enter network followed by the number of the Frame Relay interface that you want to monitor.
Monitor>network 1
Circuit <NET-1>
Circuit <NET-1> frmgr
Frame Relay Manager Console
FRMGR <WAN>
FRMGR Config <WAN>),Config> prompt, enter list interfaces to see a list of interfaces configured on the router.
Config>set data-link frame-relay
Interface Number [0]? 1
Config>enable lan-emulation
Interface number [0]? 1
Config>network
What is the network number [0]? 1
Circuit Configuration
Circuit Config <NET-1>
Circuit Config <NET-1> frlane
Frame Relay LAN Emulation User Configuration
FRLANE Config <NET-1>
FLANE <NET-#>), Monitor> prompt, enter list interfaces to see a list of interfaces configured on the router. Enter network followed by the number of the Frame Relay interface that you want to monitor.
Monitor>network 1
Circuit <NET-1>
Circuit <NET-1> frlane
Frame Relay LAN Emulation Console
FRLANE <NET-1>
FRVC <NET-#>), Monitor> prompt, enter list interfaces to see a list of interfaces configured on the router.
Monitor>network 1
Circuit <NET-1>
Circuit <NET-1> frvc
Frame Relay Virtual Circuit Console
FRVC <NET-1>
The next sections describe each of these tasks. Once you finish configuring Frame Relay, restart the router for your configuration to take effect.
Frame Relay Worksheet
To configure Frame Relay, you need the following information. Your Frame Relay provider or network administrator can give you this information.
| Parameter | Default | Your Setting |
|---|---|---|
| Whether to use FRLANE or FRVC | FRVC | |
| LMI type (LMI Rev 1, ANSI, or CCITT) | LMI ANSI | |
| CIR monitoring, enabled or disabled | Disabled | |
| Congestion monitoring, enabled or disabled | Enabled | |
| For each PVC: | ||
| Committed Information Rate (CIR) in bps | 64,000 | |
| Committed Burst Size in bits | 64,000 | |
| Excess Burst Size in bits | 0 | |
| Line speed of the serial line in bps | 64,000 | |
| Maximum frame size of the serial line in bytes | 2048 |
Configuring Frame Relay Manager
Follow these steps to configure the Frame Relay Manager (FRMGR).
FRMGR Config <WAN>
prompt.
FRMGR Config <WAN> add permanent-virtual-circuit
Circuit number [16]?
Committed Information Rate (CIR) in bps [64000]?
Committed Burst Size (Bc) in bits [64000]?
Excess Burst Size (Be) in bits [0]?
Assign circuit name? rochester
FRMGR Config <WAN> set lmi-type rev1
| Parameter | Default |
|---|---|
| Cable Type* | RS-232 DTE |
| Clocking* | External |
| Encoding | NRZ |
| Frame size | 2048 bytes |
| Idle | Flag |
| Speed | 64,000 bps |
| Transmit delay | 0 |
* Not configurable on all platforms. Some platforms automatically detect the cable type and set clocking to internal or external.
To set these parameters, enter sl at the circuit configuration prompt, and then use the set hdlc commands.
Circuit Config <NET-1> sl
Serial Line Configuration
Serial Config <WAN> set hdlcSpace
The choices/prefixes are (a complete list):
CABLE
CLOCKING
ENCODING
FRAME-SIZE
IDLE
SPEED
TRANSMIT-DELAY
BRI Config <WAN>.You can also use the set idle-timeout and set redial-timer commands to control connections to the Frame Relay switch.FRMGR Config <WAN2-1> set switch-address-name
Assign switch address name? rochester
For information on how to set up ISDN, see Using the ISDN Interface.
Configuring Frame Relay LAN Emulation
Follow these steps to configure FRLANE.
Config>add interface frame-relay
Adding interface 2 linked to base device WAN.
Config>enable lan-emulation
Interface number [0]? 1Config>enable lan-emulation
Interface number [0]? 2
FRLANE Config <NET-#>
prompt.
FRLANE Config <NET-1> add circuit
Circuit number [16]?
Is circuit required for interface operation? [N]?
FRLANE Config <NET-1> enable lane-group
FRLANE Config <NET-1> add protocol-address
Protocol name or number [IP]?
IP Address [0.0.0.0]? 10.1.65.3
Config>add interface frame-relay
Adding interface 2 linked to base device WAN.
Config>disable lan-emulation
Interface number [0]? 2
Config>network
What is the network number [0]? 2
Circuit Configuration
Circuit Config <NET-2> set destination
Assign destination address name []? rochester
Running PPP over FRVC
You can optionally set up an FRVC to send PPP data over the FRVC. By also enabling PPP data compression, you can compress the data that the router sends over the FRVC. To use PPP over FRVC, enable it at the configuration prompt and then set up PPP as you normally would.
Note: Make sure you also enable PPP over FRVC on the remote router to which this FRVC connects.Config>enable ppp-over-frvc
Interface Number [0]? 2
Note:
The FRMGR configuration applies to all interfaces on a physical Frame Relay device. If you have multiple interfaces on one device, it does not matter which Circuit Config <NET-#> prompt for the device you use to get to the FRMGR prompt.
Space twice after you type a command to display the available options for each command. Enter help for information about using the command line interface.
[C] means the command is available at the FRMGR Config <WAN> prompt.
[M] means the command is available at the FRMGR <WAN> prompt.
| Command | Function |
|---|---|
| Add [C] | Adds PVCs to the FRMGR configuration. |
| Change [C] | Changes the configuration of PVCs that were added using the add command. |
| Clear [M] | Resets all statistics on the Frame Relay device. |
| Delete [C] | Deletes any previously added PVCs. |
| Disable [C] [M] | Disables circuit and congestion monitoring, LMI, and the use of orphan circuits. |
| Enable [C] [M] | Enables circuit and congestion monitoring, LMI, and the use of orphan circuits. |
| Exit [C] [M] | Returns to the previous prompt. |
| List [C] [M] | Displays the current configuration of LMI and PVCs. At the monitoring prompt, it also displays statistics and the status of PVCs. |
| Remove [C] | Deletes any previously added PVCs. |
| Set [C] [M] | Sets the Frame Relay management options, idle timeout, redial timer, and a switch address name. |
Add [C]
Adds a PVC to the FRMGR configuration. Add a PVC if you
have disabled LMI,
do not want to use orphan circuits to a specific destination,
need to change the default information rates for a circuit, or
are running IPX or bridging over an FRLANE interface. In this case, you must either
assign a name to the PVC that you add here and use that name when you set up IPX or bridging, or
use the circuit number that you add here in your IPX or bridging configuration.
In the FRLANE configuration, you also need to add a circuit that has the same number as the PVC you add here. See add circuit.
Example: add permanent-virtual-circuit
Circuit Number [16]?
Committed Information Rate (CIR) in bps [64000]?
Committed Burst Size (Bc) in bits [64000]?
Excess Burst Size (Be) in bits [0]?
Assign Circuit name []?
|
Circuit Number
| The circuit number in the range of 16 to 1007. |
|
Committed Information Rate (CIR)
| The data rate in bits per second (bps) that the Frame Relay provider commits to support for the PVC under normal, uncongested conditions. |
|
Committed Burst Size
|
The maximum amount of data in bits that the network agrees to deliver during a measurement interval equal to Committed Burst (Bc) Size/CIR seconds. See Committed Burst (Bc) Size. |
|
Excess Burst Size
|
The maximum amount of uncommitted data in bits in excess of Committed Burst Size that the router attempts to deliver during a measurement interval equal to (Committed Burst Size/CIR) seconds. See Excess Burst (Be) Size. |
|
Assign Circuit Name
| A name that describes the circuit. Assigning a name is optional. |
Change [C]
Changes the configuration of PVCs.
Example: change permanent-virtual-circuit
Circuit Number [16]?
Committed Information Rate in bps [64000]?
Committed Burst Size (Bc) in bits [64000]?
Excess Burst Size (Be) in bits [0]?
Assign Circuit Name: []?
Note:
You can also clear statistics using the clear command at the Monitor> prompt.
clear
Delete [C]
Deletes PVCs from the FRMGR configuration.
Example: delete permanent-virtual-circuit
Circuit number [16]? 20
congestion-monitor
Disables congestion monitoring, which prevents FRMGR from varying the circuit's information rate in response to network congestion. The default is enabled.
Example: disable congestion-monitor
lmi
Disables all management activity. The default is LMI ANSI enabled. Disabling LMI causes the software to mark all PVCs that you added as present and active. If the status of a PVC changes, FRMGR has no way to learn of the change. FRMGR also has no way to learn about orphan circuits. This command is available only at the FRMGR Config <WAN> prompt.
Note: Disabling LMI allows for normal operation or end-to-end Frame Relay testing in the absence of a real network or management interface. For end-to-end Frame Relay testing, add PVCs on both ends of the link and assign the same circuit number to them.
Example:disable lmi
orphan-circuits
Prohibits the use of orphan circuits on the device. The default is orphan circuits enabled. Disabling orphan circuits adds a measure of security to your network by preventing unauthorized entry into your network from a nonconfigured circuit.
This command is available only at the FRMGR Config <WAN> prompt.
Example: disable orphan-circuits
Enable [C] [M]
Enables circuit and congestion monitoring, LMI, and the use of orphan circuits.
See CIR Monitoring.
congestion-monitor
Enables congestion monitoring, which allows a circuit's information rate to vary in response to network congestion. The default is enabled.
Example: enable congestion-monitor
lmi
Enables management activity. The default is LMI ANSI enabled. Use enable lmi to resume LMI management if you previously disabled LMI.
To change the management type, use the set set lmi-type command
This command is available only at the FRMGR Config <WAN> prompt.
orphan-circuits
Allows FRMGR to use orphan circuits, which is the default. The CIR of orphan circuits is 64000 bps, the committed burst (Bc) size is 64000 bps, and the excess burst (Be) size is 0.
This command is available only at the FRMGR Config <WAN> prompt.
Example: enable orphan-circuits
Exit [C] [M]
Returns to the previous prompt.
exit
Circuit Config <NET-1>
List [C]
Displays currently configured management and PVC information.
lmi
Displays logical management and related configuration information.
Frame Relay LMI Configuration
LMI enabled = Yes LMI DLCI = 0
LMI type = ANSI LMI Orphans OK = Yes
Congestion monitoring = Yes CIR monitoring = No
PVCs P1 allowed = 64 CIR monitor adjustment = 1
Timer T1 seconds = 10 Counter N1 increments = 6
LMI N2 error threshold = 3 LMI N3 error threshold window = 4
MIR % of CIR = 25 IR % increment = 12
IR % decrement = 25 Redial timer = 0
Idle timeout = 0
Switch address name = seattle
|
LMI enabled
| Indicates whether the management feature is enabled. |
|
LMI DLCI
| The circuit number over which LMI sends status enquiries and responses. ANSI and CCIT use 0 and Rev1 uses 1023. |
|
LMI Type
| The LMI type set, Rev1, ANSI, or CCITT. |
|
LMI Orphans OK
| Indicates whether nonconfigured circuits are available for use. |
|
Congestion monitoring
| Indicates whether the congestion monitoring feature that responds to network congestion is enabled. |
|
CIR monitoring
| Indicates whether the circuit monitoring feature that enforces the transmission rate is enabled. |
|
PVCs P1 allowed
| Number of PVCs allowed for use with this device. |
|
CIR monitor adjustment
| Used to calculate the maximum burst transmission speed allowed over a PVC when CIR monitoring is enabled. The maximum burst transmission speed is the CIR value times the CIR monitor adjustment. If you specify a Committed Burst Size, the software ignores this value. |
|
Timer T1 seconds
| Rate at which FRMGR performs a sequence number exchange with management. |
|
Counter N1 increments
| The interval in seconds at which FRMGR queries management for complete PVC status. |
|
LMI N2 error threshold
| Number of management event errors that reset the connection to the Frame Relay switch. |
|
LMI N3 error threshold window
| Number of events in the management window. |
|
MIR % of CIR
| Minimum IR, which is a percentage of CIR. |
|
IR % Increment
| Percentage by which FRMGR increases the IR each time it receives a frame without BECN until it reaches the maximum IR. |
|
IR % Decrement
| Percentage by which FRMGR decreases the IR each time it receives a frame that contains BECN until it reaches the minimum IR. |
|
Redial timer
|
Setting of the redial timer. See set redial-timer. |
|
Idle timeout
|
Setting of the idle timeout. See set idle-timeout. |
|
Switch address name
|
Shows an address name if you set one using the set switch-address-name command. |
permanent-virtual-circuits
Displays all PVCs configured on the FRMGR.
Example: list permanent-virtual-circuit
Maximum PVCs allowable = 64
Total PVCs configured = 2
Circuit Circuit Circuit CIR Burst Excess
Name Number Type in bps Size Burst
-------------------- ------- ------- ------ ----- -----
houston 16 Permanent 64000 64000 0
portland 32 Permanent 64000 64000 0
List [M]
Displays statistics and configuration information.
circuit
Displays statistics and configuration information for the circuit that you specify.
Circuit number [16]?
Circuit name = houston
Circuit state = Idle Circuit is orphan = No
Frames transmitted = 0 Bytes transmitted = 0
Frames received = 0 Bytes received = 0
Total FECNs = 0 Total BECNs = 0
Times congested = 0 Times Inactive = 0
CIR in bits/second = 9600 Current Info Rate = 9600
Committed Burst (Bc) = 64000 Excess Burst (Be) = 0
Xmit frames dropped due to queue overflow = 0
lmi
Displays statistics and configuration information related to the logical management of the Frame Relay device.
Management Status:
------------------
LMI state = Initial
LMI enabled = Yes LMI DLCI = 0
LMI type = ANSI LMI orphans OK = Yes
LMI sequence interval seconds = 10
Congestion monitoring = Yes CIR monitoring = No
PVCs P1 allowed = 64 Interface MTU in bytes = 2048
Line access rate bps = 9600 CIR monitor adjustment = 1
Timer T1 seconds = 10 Counter N1 increments = 6
LMI N2 threshold = 3 LMI N3 threshold window = 4
MIR % of CIR = 25 IR % increment = 12
IR % decrement = 25 Redial timer = 0
Idle timeout = 0
Switch address name =
Current receive sequence = 0
Current transmit sequence = 0
Total status enquiries = 0 Total status responses = 0
Total sequence requests = 0 Total responses =
PVC Status:
-----------
Total allowed = 64 Total configured = 1
Total active = 0 Total congested = 0
Total left net = 0 Total join net = 0
|
LMI state
| State of the circuit. |
|
LMI enabled
| Indicates whether the management features are enabled. |
|
LMI DLCI
| The circuit number over which LMI sends status inquiries and responses. ANSI and CCIT use 0 and Rev1 uses 1023. |
|
LMI type
| The LMI type set, Rev1, ANSI, or CCITT. |
|
LMI Orphans OK
| Indicates whether nonconfigured circuits are available for use. |
|
LMI sequence interval seconds
| Interval that management uses when exchanging keepalive information with an end station. |
|
Congestion monitoring
| Indicates whether the congestion monitoring feature that responds to network congestion is enabled. |
|
CIR monitoring
| Indicates whether the circuit monitoring feature that enforces the transmission rate is enabled. |
|
PVCs P1 allowed
| Number of PVCs allowed for use with this device. |
|
Interface MTU in bytes
| Size of user data contained in the Frame Relay frame. |
|
Line access rate bps
| Physical data rate of the Frame Relay device. |
|
CIR monitor adjustment
| Used to calculate the maximum burst transmission speed allowed over a circuit when CIR monitoring is enabled. The maximum burst transmission speed is the CIR value times the CIR monitor adjustment. If you specify a Committed Burst Size, the software ignores this value. |
|
Timer T1 seconds
| Rate at which FRMGR performs a sequence number exchange with management. |
|
Counter N1 increments
| The interval in seconds at which FRMGR queries management for PVC status. |
|
LMI N2 threshold
| Number of management event errors that reset the connection to the Frame Relay switch. |
|
LMI N3 threshold window
| Number of events in the management window. |
|
MIR % of CIR
| Minimum IR, which is a percentage of CIR. |
|
IR % Increment
| Percentage by which FRMGR increases the IR each time it receives a frame without BECN until it reaches the maximum IR. |
|
IR % Decrement
| Percentage by which FRMGR decreases the IR each time it receives a frame that contains BECN until it reaches the minimum IR. |
|
Redial timer
|
Setting of the redial timer. See set redial-timer. |
|
Idle timeout
|
Setting of the idle timeout. See set idle-timeout. |
|
Switch address name
|
Shows a switch address name if you set one using the set switch-address-name command. |
|
Current receive sequence
| Current receive sequence number that FRMGR received from management. |
|
Current transmit sequence
| Current transmit sequence number that FRMGR sent to management. |
|
Total status enquiries
| Enquiries that management made as to the status of the Frame Relay device. |
|
Total status responses
| Responses that FRMGR received from management in response to status enquiries. |
|
Total sequence requests
| Sequence number requests that FRMGR made to management. |
|
Total responses
| Sequence number responses received in response to management sequence number exchange. |
|
Total allowed
| Virtual circuits allowed (including orphans) for use with this device. |
|
Total configured
| Configured PVCs for this interface. |
|
Total active
| Active virtual circuits on this interface. |
|
Total congested
| Virtual circuits that are throttled down because of congestion within the network. |
|
Total left net
| Virtual circuits that are no longer on the network. |
|
Total join net
| Virtual circuits that have joined the network. |
permanent-virtual-circuits
Shows the circuits that FRMGR knows about, either PVCs or orphan circuits.
Example: list permanent-virtual-circuits
Orphan Type/ Frames Frames
Circuit# Circuit Name Circuit State Transmitted Received
-------- ------------------------ ------- ----- ----------- ----------
16 houston No P/I 0 0
A - Active I - Inactive R - Removed
P - Permanent M - Multicast C - Congested
Remove [C]
Deletes PVCs from the FRMGR configuration.
Example: remove permanent-virtual-circuit
Circuit number [16]? 20
Set [C]
Sets the Frame Relay management options, idle timeout, redial timer, and a switch address name.
The default is 60. The range is 1 to 65535 seconds.
Idle timeout in seconds (1-65535) [60]?
When network congestion clears, each time the router receives a frame without BECN, it increases the IR by this percentage until it reaches the maximum IR. The minimum percentage is 1, and the maximum percentage is 100. The default is 12.
When network congestion occurs, each time the router receives a frame containing BECN, it decreases the IR by this percentage until it reaches the minimum IR. The minimum percentage is 1, and the maximum percentage is 100. The default is 25.
The minimum IR is a percentage of CIR, and is the lower limit of the information rate. The minimum percentage is 1, and the maximum percentage is 100. The default is 100.
See Congestion Notification and Avoidance.
IR adjustment % increment [12]?
IR adjustment % decrement [25]?
Minimum IR as % of CIR [100]?
| Type | Conforms to . . . |
| rev1 | LMI Revision 1, (Stratacom's Frame Relay LMI Specification). |
| ansi | ANSI T1.617 ISDN-DSS1-Signalling Specification for Frame Relay Bearer Service, Annex D. |
| ccitt | Annex A of CCITT Recommendation Q.933 - DSS1 Signalling Specification for Frame Mode Basic Call Control. |
n1-parameter
Sets the number of T1 timer intervals that must expire before Frame Relay makes a complete PVC status enquiry. The range is 5 to 30. The default is 2.
Parameter N1 [2]?
The range is 1 to 10. The default is 3. Set this parameter less than or equal to the n3-parameter.
Parameter N2 [3]?
Parameter N3 [4]?
Parameter P1 [64]?
The default of 0 (zero) means FRMGR does not redial automatically. To set up FRMGR to redial automatically, enter the number of seconds FRMGR waits after it disconnects before attempting another connection. The range is 0 to 65535 seconds.
Redial timer in seconds (0-65535, 0 means no redial) [0]?
BRI Config <WAN>.
Example: set switch-address-name
Assign switch address name? seattle
Parameter T1 [10]?
Circuit Number [16]?
Committed Information Rate in bps [64000]?
Committed Burst Size (Bc) in bits [64000]?
Excess Burst Size (Be) in bits [0]?
When network congestion clears, each time the router receives a frame without BECN, it increases the IR by this percentage until it reaches the maximum IR. The minimum percentage is 1, and the maximum percentage is 100. The default is 12.
When network congestion occurs, each time the router receives a frame containing BECN, it decreases the IR by this percentage until it reaches the minimum IR. The minimum percentage is 1, and the maximum percentage is 100. The default is 25.
The minimum IR is a percentage of CIR, and is the lower limit of the information rate. The minimum percentage is 1, and the maximum percentage is 100. The default is 100.
IR adjustment % increment [12]?
IR adjustment % decrement [25]?
Minimum IR as % of CIR [100]?
Press Space twice after you type a command to display the available options for each command. Enter help for information about using the command line interface.
[C] means the command is available at the FRLANE Config <NET-#> prompt.
[M] means the command is available at the FRLANE <NET-#> prompt.
Note:
To display these prompts, you must first enter enable lan-emulation at the Config> prompt.
| Command | Function |
|---|---|
| Add [C] | Adds a circuit or destination protocol address. |
| Change [C] | Changes circuits or protocol addresses that were added with the add command. |
| Clear [M] | Resets statistics related to FRLANE. |
| Delete [C] | Deletes circuits or protocol addresses that were added with the add command. |
| Disable [C] [M] | Disables LAN emulation groups, multicast emulation, protocol broadcast, and the no-PVC flag. |
| Enable [C] [M] | Enables LAN emulation groups, multicast emulation, protocol broadcast, and the no-PVC flag. |
| Exit [C] [M] | Returns to the previous prompt. |
| List [C] [M] |
At the configuration prompt, displays FRLANE circuits, LAN emulation configuration, and any protocol address mappings. At the monitoring prompt, displays statistics and configuration information for FRLANE circuits. |
| Remove [C] | Deletes circuits or protocol addresses that were added with the add command. |
Add [C]
Adds a circuit or destination protocol address.
To run IPX or bridging over FRLANE,
Configuring a circuit as required causes all circuits on the FRLANE interface to go down when a required circuit becomes unavailable. Instead of configuring a circuit as required to trigger WAN Reroute, you can enter enable no-pvc, which causes the interface to declare itself down if there are no active circuits.
Circuit Number [16]?
Is circuit required for interface operation? [N]?
This parameter prompts you for different information depending on the type of protocol address you are adding.
Protocol name or number [IP]?
IP Address [0.0.0.0]?
Circuit number [16]?
Host Number (in hex)[]?
Circuit number [16]?
Network number (1-65279) []?
Node number (1-253) []?
Circuit number [16]?
Change [C]
Changes circuits or protocol addresses that were added with the add command.
Configuring a circuit as required causes all circuits on the interface to go down when a required circuit becomes unavailable. Instead of configuring a circuit as required to trigger WAN Reroute, you can enter enable no-pvc, which causes the interface to declare itself down if there are no active circuits.
Circuit number [16]?
Is circuit required for interface operation? [N]? y
Example: change protocol-address
Protocol name or number [IP]?
IP Address [0.0.0.0]? 128.185.10.2
Circuit number [16]?
clear
Delete [C]
Deletes circuits or protocol addresses that you added with the add command.
Circuit number [16]?
Example: delete protocol-address
Protocol name or number [IP]?
IP Address [0.0.0.0]? 128.185.10.2
Circuit number [16]?
multicast-emulation
Disables multicast emulation on all active VCs on this interface. Multicast emulation allows protocols requiring multicast to work properly over the FRLANE interface. Protocols that use multicast are IP, IPX, and ARP. The default setting for this feature is enabled. If you disable this feature, you must add static destination protocol addresses.
Example: disable multicast-emulation
protocol-broadcast
Prevents routing protocols that use broadcasts, such RIP, from running over the FRLANE interface. The default setting for this feature is enabled.
Example: disable protocol-broadcast
no-pvc
Disables the no-PVC flag on the FRLANE interface. The WAN Reroute feature uses the no-PVC flag. When enabled, this flag triggers WAN Reroute to bring up the alternate circuit by causing the interface to declare itself down if there are no active circuits.
Enable [C] [M]
Enables LAN emulation groups, multicast-emulation, protocol-broadcast, and the no-PVC flag.
multicast-emulation
Enables multicast emulation on all active VCs on this interface. Multicast emulation allows protocols requiring multicast to work properly over the FRLANE interface. Protocols that use multicast are IP, IPX, and ARP. The default is enabled.
Example: enable multicast-emulation
protocol-broadcast
Allows routing protocols that use broadcasts, such as RIP, to run over the FRLANE interface. Multicast emulation must be enabled for protocol broadcast to work properly. The default setting for this feature is enabled.
Example: enable protocol-broadcast
no-pvc
Enables the no-PVC flag on the FRLANE interface. The WAN Reroute feature uses the no-PVC flag. When enabled, this flag triggers WAN Reroute to bring up the alternate circuit by causing the interface to declare itself down if there are no active circuits available.
Exit [C] [M]
Returns to the previous prompt.
Circuit Config <NET-1>
List [C]
Displays FRLANE VCs, LAN emulation configuration, and any protocol address mappings.
circuits
Displays circuits that you manually added for FRLANE and whether or not the circuits are required.
Frame Relay LAN Emulation Configured Circuits
Circuit# Required
-------- --------
16 No
Frame Relay LAN Emulation Configuration
LANE emulation group = Disabled
Protocol broadcast = Yes Multicast emulation = No
Down if no circuits = No
Example: list protocol-addresses
Frame Relay Protocol Address Translations
Protocol Type Protocol Address Circuit Number
------------- ---------------- --------------
IP 128.185.10.2 16
|
Protocol Type
| The name of the protocol running over the interface. |
|
Protocol Address
| The address of the protocol running over the interface. |
|
Circuit Number
| The VC that is running the protocol. |
List [M]
Displays statistics and configuration information for FRLANE circuits.
Frame Relay LAN Emulation
State = Up
LAN emulation group = Disabled
Protocol broadcast = No Emulate multicast = Yes
Down if no circuits = No
Active circuits = 0 Total circuits = 1
Type/ Frames Frames
Circuit# Circuit Name State Transmitted Received
-------- ------------------------ ------ ----------- ----------
16 houston S/I 0 0
D - Dynamic S - Static * - Required
A - Active I - Inactive
circuits
Displays statistics for the circuit that you specify.
Circuit number [16]?
Circuit name = houston
Circuit state = Inactive
Frames transmitted = 0 Bytes transmitted = 0
Frames received = 0 Bytes received = 0
Remove [C]
Deletes circuits or protocol addresses that you added with the add command.
Circuit number [16]?
Example: remove protocol-address
Protocol name or number [IP]?
IP Address [0.0.0.0]? 128.185.10.2
Circuit number [16]?
Press Space twice after you type a command to display the available options for each command. Enter help for information about using the command line interface.
There is no configuration prompt for FRVC.
[M] means the command is available at the FRVC <NET-#> prompt.
| Command | Function |
|---|---|
| Clear [M] | Resets all statistics for Frame Relay Virtual Circuits. |
| Exit [M] | Returns to the previous prompt. |
| List [M] | Displays statistics for the virtual circuit. |
Clear [M]
Clears all statistics for Frame Relay Virtual Circuits.
clear
Exit [M]
Returns to the previous prompt.
exit
Circuit <NET-1>
list
Frame Relay Virtual Circuit
Circuit name =
State = Down
Frames transmitted = 0 Bytes transmitted = 0
Frames received = 0 Bytes received = 0