Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Help with Interfaces Errors on Satellite WAN Circuit

Hello all,

I have recently connected my site to a remote office using a 9.744 Mbps point-to-point serial circuit over Satellite. I am seeing very strange errors on the interfaces and would appreciate assistance. Please reference the attached network diagram with the follow-up post containing the "show interfaces" below. The connection from my building to the satellite teleport is over ATM. I am seeing "output drops" on both sides of ATM circuit. The ATM circuit is one 9.744 Mbps PVC. I am also seeing errors on both HSSI interfaces. The HSSI circuit is timed off the satellite modem that is connected to the HSSI interface of Router B. I noticed by doing a show controllers that the receicved timing on the HSSI interface moves from 9743538 to 9745120 approximtely once every 30 seconds. However, I can not directly correlate the timing drift to the interface errors.

Thank you for your help.

5 REPLIES
New Member

Re: Help with Interfaces Errors on Satellite WAN Circuit

Router A ATM Interface (ATM 2/0):

RouterA#sh int atm 2/0

ATM2/0 is up, line protocol is up

Hardware is RS8234 ATM DS3

Description: ATM Trunk

MTU 4470 bytes, sub MTU 4470, BW 45000 Kbit, DLY 190 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ATM, loopback not set

Encapsulation(s): AAL5

1023 maximum active VCs, 2 current VCCs

VC Auto Creation Disabled.

VC idle disconnect time: 300 seconds

Last input 00:00:01, output 00:00:00, output hang never

Last clearing of "show interface" counters 5w0d

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 8901043

Queueing strategy: Per VC Queueing

30 second input rate 131000 bits/sec, 14 packets/sec

30 second output rate 47000 bits/sec, 14 packets/sec

121292189 packets input, 741762298 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 5 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

112122802 packets output, 3956918578 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

Router B ATM Interface (atm 4/0):

RouterB#sh int atm 4/0

ATM4/0 is up, line protocol is up

Hardware is RS8234 ATM DS3

Description: ATM

MTU 4470 bytes, sub MTU 4470, BW 9744 Kbit, DLY 190 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ATM, loopback not set

Encapsulation(s): AAL5

1023 maximum active VCs, 1 current VCCs

VC Auto Creation Disabled.

VC idle disconnect time: 300 seconds

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 1d22h

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 194973

Queueing strategy: Per VC Queueing

30 second input rate 43000 bits/sec, 8 packets/sec

30 second output rate 8000 bits/sec, 7 packets/sec

13834546 packets input, 3469090240 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

15460961 packets output, 123454412 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

New Member

Re: Help with Interfaces Errors on Satellite WAN Circuit

Router B HSSI interface (hssi 3/0):

RouterB#sh int hssi 3/0

Hssi3/0 is up, line protocol is up

Hardware is M1T-HSSI-B

Description: SATCOM LINK

Internet address is 10.1.2.5/30

MTU 4470 bytes, BW 9744 Kbit, DLY 200 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, LCP Open

Open: IPCP, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input 00:00:03, output 00:00:00, output hang never

Last clearing of "show interface" counters 02:52:13

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

30 second input rate 6000 bits/sec, 6 packets/sec

30 second output rate 0 bits/sec, 0 packets/sec

128737 packets input, 17418447 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 parity

584 input errors, 574 CRC, 0 frame, 5 overrun, 0 ignored, 5 abort

138174 packets output, 87933979 bytes, 0 underruns

0 output errors, 0 applique, 0 interface resets

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions LC=down CA=up TM=down LB=down TA=up LA=down

HSSI DTE, received clockrate 9745120

HSSI DTE, received clockrate 9743538

Router C HSSI Interface (hssi 1/0):

RouterC#sh int hssi 1/0

Hssi1/0 is up, line protocol is up

Hardware is M1T-HSSI-B

Description: SATCOM LINK

Internet address is 10.1.2.6/30

MTU 4470 bytes, BW 9744 Kbit, DLY 200 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation PPP, LCP Open

Open: IPCP, crc 16, loopback not set

Keepalive set (10 sec)

Restart-Delay is 0 secs

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 2d02h

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 9917

Queueing strategy: fifo

Output queue: 0/40 (size/max)

30 second input rate 24000 bits/sec, 8 packets/sec

30 second output rate 7000 bits/sec, 8 packets/sec

15556907 packets input, 1154275136 bytes, 0 no buffer

Received 0 broadcasts, 202 runts, 0 giants, 0 throttles

0 parity

4858695 input errors, 2514675 CRC, 0 frame, 1380169 overrun, 0 ignored, 963851 abort

18890347 packets output, 1964671150 bytes, 2316 underruns

Hall of Fame Super Gold

Re: Help with Interfaces Errors on Satellite WAN Circuit

Hi,

only router C has a severely errored interface, can you have the satellite modem checked for correct SNR as likely the problem lies in there.

As you see on router B the HSSI clock can fluctuate a little without causing any problem.

New Member

Re: Help with Interfaces Errors on Satellite WAN Circuit

Thank you very much for the reply. We're currently looking into replacing the SAT modem connected to router C. The circuit had been running pretty well for about 4 weeks until we begun seeing errors this past week. What concerns me are the output packet drops on the ATM interface. I have noticed the clock fluctuating on the HSSI interface from 9743538 to 9745528, while the ATM is a constant 9744000. Do you think that the mismatch of speeds could be causing this? If not, do you have any ideas on how I could troubleshoot?

Hall of Fame Super Gold

Re: Help with Interfaces Errors on Satellite WAN Circuit

Hi, if had worked 4 fine weeks it's just a matter of checking something on the dish and related equipment and fix it. For example a faulty lnb can bring SNR low enough for the error correction on the sat link not suffice anymore.

137
Views
0
Helpful
5
Replies