Configuring ATM-PPP Internetworking
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Contents
Introduction
This document contains a simple ATM to Point-to-Point Protocol (PPP) configuration. It is intended to serve as an example of how to set up ATM-PPP Internetworking between Cisco routers and Cisco or StrataCom WAN switches. For more detail on the configuration of the various components, refer to the Technology Information Documentation, PPP Over ATM, and Virtual Access PPP Features in Cisco IOS.
Prerequisites
Requirements
There are no specific requirements for this document.
Components Used
This document is not restricted to specific software and hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Conventions
For more information on document conventions, refer to the Cisco Technical Tips Conventions.
Configuring the MGX 8220 Shelf
Follow this procedure to configure the MGX 8220 shelf:
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Verify that the line exists.
mgx8220a.1.9.FRSM.a > dsplns Line Conn Type Status/Coding Length XmtClock Alarm Stats Type Source Alarm ---- ---- --------- ------------- -------- -------- ----- ----- 9.1 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim 9.2 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim 9.3 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim 9.4 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim LineNumOfValidEntries: 4 Syntax : dsplns
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Enable the line.
mxg8820a.1.9.FRSM.a > addln 2 mxg8820a.1.9.FRSM.a >
If this works, then you will get only the prompt back; you can issue the dsplns command again, to ensure that the status is enabled.
mgx8220a.1.9.FRSM.a > dsplns Line Conn Type Status/Coding Length XmtClock Alarm Stats Type Source Alarm ---- ----- --------- ------ ------ -------- -------- ----- ----- 9.1 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim 9.2 DB-15 dsx1ESF Ena/dsx1B8ZS 0-110 ft LocalTim No No 9.3 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim 9.4 DB-15 dsx1ESF Dis/dsx1B8ZS 0-110 ft LocalTim LineNumOfValidEntries: 4 Syntax : dsplns
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Use the cnfln command to change the line parameters to meet the needs of your environment.
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Add the logical port configuration.
This example demonstrates how to set up a full T1 port (24 channels) between the 3640 and the MGX 8220 shelf, with a port type of frame forward:
mgx8220a.1.9.FRSM.a > addport 1 2 2 1 24 3
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Issue the dspports command to verify that the port has been added and that the configuration is correct.
mgx8220a.1.9.FRSM.a > dspports Port Ena/Speed EQServ SignalType T391 T392 N391 N392 N393 Type Alarm Ratio ------ --------- ------ ------------ ---- ---- ---- ---- ---- -------- ----- 9.2.1 Add/1536k 1 NoSignalling 10 15 6 3 4 frForwar No Number of ports: 1 PortDs0UsedLine1: 0x00000000 PortDs0UsedLine2: 0x00ffffff PortDs0UsedLine3: 0x00000000 PortDs0UsedLine4: 0x00000000 PortNumNextAvailable: 36 Syntax : dspports -
Add the frame forwarding channel.
Now you are ready to add the frame forwarding channel. This step demonstrates how to add a connection using logical channel number 100 on logical port 1 (timeslots 1 to 24). It is configured with data link connection identifier (DLCI) 0 with a CIR of 1536000 using frame forwarding. The concept of DLCI is slightly misleading. Frame forwarding connections do not direct traffic based on the DLCI.
In this example, the DLCI value is used as a place holder:
mgx8220a.1.9.FRSM.a > addchan 100 1 0 1536000 5 SAR-MSG>>LCN 100 is enabled
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Verify the channel:
mgx8220a.1.9.FRSM.a > dspchans DLCI Chan EQ I/EQDepth I/EQDEThre I/EECNThre Fst/ DE Type Alarm ------------ ---- -- ----- ----- ----- ----- ----- ----- --- --- ----- ----- 9.2.1.1000 100 2 65535/65535 32767/32767 6553/6553 Dis/Dis frFor No Number of channels: 1 ChanNumNextAvailable: 23 Syntax : dspchans
Configuring the BPX
Follow this procedure to configure the BPX:
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Make sure that the ATM Service Interface (ASI) port is up and active.
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Up the line:
upln 10.2
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Issue the dsplns command to verify that the line is operational.
bpx8620a TN Cisco BPX8620 9.3.45 Jul. 10 2003 05:25 EDT Line Type Current Line Alarm Status 10.1 OC3 Major - Loss of Sig (RED) 10.2 OC3 Clear - OK 11.1 T3 Major - Loss of Sig (RED) 11.2 T3 Clear - OK Last Command: dsplns
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Issue the upport command to up the port.
bpx8620a TN Cisco BPX8620 9.3.45 Jul. 10 2003 05:23 EDT Port: 10.2 [ACTIVE ] Interface: MMF-2 Type: UNI %Util Use: Disabled Speed: 353208 (cps) Shift: SHIFT ON HCF (Normal Operation) VBR Queue Depth: 492 Protocol: ILMI VPI.VCI: 0.16 ILMI Polling Enabled N Trap Enabled Y T491 Polling Interval 30 N491 Error Threshold 3 N492 Event Threshold 4 Last Command: upport 10.2
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Issue the dspport command to make sure the port is active.
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Issue the cnfport command to make any changes to the port that are necessary to adapt the port configuration to your environment.
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Add the shelf to the network.
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Up the trunk on the BNI port 1.1:
uptrk 1.1
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Add the MGX 8220 shelf connected to 1.1:
addshelf 1.1 A
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Verify that the MGX 8220 shelf exists on the network.
Issue the dspnode command to see if the MGX 8220 shelf is listed.
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Add the connection from the ASI (port 10.2) to the BNI (1.1) where the MGX 8220 shelf is located.
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Use the slot number (9) and channel number (100) configured in the Configuring the MGX 8220 Shelf section.
addcon 10.2.0.32 bpx8620a 1.1.9.100 atfr * 1536 * * * * * * * * *
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The connection can be the same node or a different node in the network.
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The quality of service and bandwidth requirements must match your network requirements. In this example, the 1536 Kbps line-rate setup on the MGX 8220 shelf is matched to the PCR, and the CIR is set equal to the SCR.
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Issue the dspcon command to verify your work.
bpx8620a TN Cisco BPX8620 9.3.45 Jul. 10 2003 05:25 EDT Conn: 10.2.0.32 bpx8620a 1.1.9.100 atfr Status:OK PCR(0+1) SCR MBS MCR SCR EN UPC CLP RM % util 1536/1536 1536/1536 1000/1000 --/-- 1/1 y y n/n 100/100 Path: Route information not applicable for local connections bpx8620a ASI-OC3 : OK bpx8620a BNI-T3 : OK Line 10.2 : OK Line 1.1 : OK OAM Cell RX: Clear NNI : OK NNI : OK Last Command: dspcon 10.2.0.32
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Configuring the ATM-Attached Router
The ATM-attached router (a Cisco 4700, in the example) must be running a version of Cisco IOS® software that supports ATM-PPP functionality. This feature was added in the 11.2(4)F image for certain platforms. Check the release notes to ensure that this functionality has been included in the Cisco IOS release on your router.
This is the required configuration for the ATM-attached router.
Note: The hostname and username items are included for the CHAP negotiation.
hostname bell username wansw-3640-2 password chappwd ! interface Virtual-Template1 ip address 10.29.69.100 255.255.255.0 cdp enable ppp authentication chap ! ! interface ATM0 no ip address ! interface ATM0.100 point-to-point atm pvc 10 0 32 aal5ppp 1536 1535 96 virtual-template 1 !
Configuring the Serial-Attached Router
This example uses a Cisco 3640 router with an integrated channel service unit (CSU), which requires configuration of the controller information as well. If you are using an external channel service unit/data service unit (CSU/DSU) to a 2500 series, for example, the controller configuration is required.
This is the configuration for the Cisco 3640 attached to the MGX 8220 shelf:
hostname wansw-3640-2 ! username bell password chappwd ! controller T1 2/0 framing esf linecode b8zs channel-group 0 timeslots 1-24 speed 64 ! interface Serial2/0:0 ip address 10.29.69.101 255.255.255.0 encapsulation ppp ppp authentication chap !
Verifying Connectivity
MGX 8220 Shelf
Issue the dspchancnt command to see the frames and the bytes that are traversing the serial interface for this particular channel:
mgx8220a.1.9.FRSM.a > dspchancnt 100
ChanNum: 100
ChanState: okay
ChanUpTime: 71
Tx Rx
--------------- ---------------
AbitState: Sending A=1 Off
ATMState: Not sending any state Not receiving any state
Total Frames: 20 21
Total Bytes: 1097 1398
Frames DE: 0 0
Bytes DE: 0 0
Frames Discarded: 0 0
Bytes Discarded: 0 0
FramesDiscXceedQDepth: 0 0
BytesDiscXceedQDepth: 0 0
FramesDiscXceedDEThresh: 0 0
Frames FECN: 0 0
Frames BECN: 0 0
FramesTagged FECN: 0 0
FramesTagged BECN: 0 0
KbpsAIR: 0 0
FramesTaggedDE: 0 0
BytesTaggedDE: 0 0
RcvFramesDiscShelfAlarm: 0
XmtFramesDiscPhyLayerFail: 0
XmtFramesDiscCRCError: 0
XmtFramesDiscReAssmFail: 0
XmtFramesDiscSrcAbort: 0
XmtFramesDuringLMIAlarm: 0
XmtBytesDuringLMIAlarm: 0
RcvFramesDiscUPC: 0
XmtFramesInvalidCPIs: 0
XmtFramesLengthViolations: 0
XmtFramesOversizedSDUs: 0
XmtFramesUnknownProtocols: 0
RcvFramesUnknownProtocols: 0
BPX
On the BPX side, issue the dspchstats command to get a cell count for the ATM interface.
bpx8620a TN Cisco BPX8620 9.3.45 Jul. 10 2003 05:25 EDT Channel Statistics for 10.2.0.32 Cleared: Sep. 10 1997 05:26 (-) PCR: 2170 cps Collection Time: 0 day(s) 00:00:36 Corrupted: NO Traffic Cells Avg CPS %util From Port : 37 1 0 To Network : 37 1 0 From Network: 44 1 0 To Port : 44 1 0 This Command: dspchstats 10.2.0.32
Routers
For the serial-connected router, issue the show interface serial command to verify that link control protocol (LCP) and any other desired control protocols are open, and to verify that traffic is passing.
wansw-3640-2# show interface serial 2/0:0
Serial2/0:0 is up, line protocol is up
Hardware is DSX1
Internet address is 10.29.69.101/24
MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, rely 255/255, load 1/255
Encapsulation PPP, loopback not set, keepalive set (10 sec)
LCP Open
Open: IPCP, CDP
Last input 00:00:04, output 00:00:04, output hang never
Last clearing of "show interface" counters 01:02:05
Input queue: 0/75/1 (size/max/drops); Total output drops: 0
Queueing strategy: weighted fair
Output queue: 0/64/0 (size/threshold/drops)
Conversations 0/1 (active/max active)
Reserved Conversations 0/0 (allocated/max allocated)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
570 packets input, 21903 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored, 1 abort
737 packets output, 25962 bytes, 0 underruns
0 output errors, 0 collisions, 50 interface resets
0 output buffer failures, 0 output buffers swapped out
4 carrier transitions
Timeslot(s) Used:1-24, Transmitter delay is 0 flags
For the ATM-connected router, issue the show interface virtual-access command to see the virtual access interface and to assess connectivity.
bell# show interface virtual-access 1
Virtual-Access1 is up, line protocol is up
Hardware is Virtual Access interface
Internet address is 10.29.69.100/24
MTU 1500 bytes, BW 100000 Kbit, DLY 100000 usec, rely 255/255, load 1/255
Encapsulation PPP, loopback not set, keepalive set (10 sec)
DTR is pulsed for 5 seconds on reset
LCP Open
Open: IPCP, CDP
Bound to ATM0.100 VCD: 10, VPI: 0, VCI: 32
Cloned from virtual-template: 1
Last input 00:00:08, output never, output hang never
Last clearing of "show interface" counters 00:43:41
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
386 packets input, 14956 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
476 packets output, 17424 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
In this example, both routers are configured to use the Cisco Discovery Protocol (CDP). A quick look at the CDP neighbor table verifies connectivity.
wansw-3640-2# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater
Device ID Local Intrfce Holdtme Capability Platform Port ID
bell Ser 2/0:0 167 R 4700 Virtual-Access1
bell# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater
Device ID Local Intrfce Holdtme Capability Platform Port ID
wansw-3640-2 Virtual-Access1153 R 3640 Ser 2/0:0
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