SatSig topic:

Tunnel Tx Errors

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Nov 12^th, 2009 at 4:03pm

Can someone please explain the cause of Tunnels Tx Errors on a line card?

Nov 12^th, 2009 at 4:19pm

Tunnel errors on the line card are an indication that there is a communication issue between the PP an line card on the tunnel subnet.
the connection from teh PP tot he line card consists of the ethernet cables from PP to Switch, the switch itself and the cable from line card to switch.
you should check the switch ports associated and see if there are any erros, check the negotiated port duplex and speed on the switch for the ports connected to the line card and to the pp and check the physical cabling in that line.
Also please check the loading on the switch.

Nov 12^th, 2009 at 4:35pm

Thank you for the quick response. I was asking because we were seeing the errors when a particular remote acquired the network, the modem is dropping out after a few minutes and then the Tunnel Tx Errors on the line card clear... Coincidence??

Nov 12^th, 2009 at 4:49pm

the modem is not acquiring correctly, the information coming from that modem to the line card then passed to the pp is not good in the iDirect IP format sense of the word.
a rare occurrence of Tunnel Tx errors but still a valid cause, so if it is purely when this single modem comes on there is an issue with it's transmission reaching the line card. do you have a ethernet sniffer program? I would use that on a PC plugged in to a duplicate switch port, matching the output to the PP, capture all traffic from the line card to the PP as you try to bring that modem online.
feel free to IM me the capture if you don't want to place it on here.
this is a much less likely cause for errors on the tunnel, but still a valid one, for some reason the PP is not bringing the remote to a stable acq state.
do you see any issues when this remote acquires on a spectrum check on the Rx side of the line card? what levels are showing oon the modems UCP on iMonitor? look at the SO, the FO and the PO and let me know those values when it acquires.

Nov 13^th, 2009 at 8:41pm

Agree with Scout, check interfaces, sw ports, etc. Ensure they are set to Auto-Neg. There is obviously something amiss on the proprietary (tunnel) side...could be hdlc related, acquisition related, or configuration related. Suggest you start by checking your interfaces, and also take a hard look at the remote that is generating the errors. Have the customer look at his interfaces as well.

Nov 13^th, 2009 at 11:52pm

Everything is looking good on the switch ports and pp interface. The errors have not occurred since yesterday when trying to activate the remote and the installer has moved on to another site (just 1 of 120 we are currently activating). When we get back to this one I will run the packet sniffer while activating as suggested.

Thanks for pointing me in the right direction!

Nov 14^th, 2009 at 1:08pm

Sounds good. Just ensure best practices are used when bringing that remote back up. Ensure power levels are contained and the system has a good 1DB compression test. Power is rarely responsible for TUN errors (normally CRC errors are the by product) but it never hurts to follow proper RF practices.

These TUN errors. What line card were they observed on? A Tx Card or Rx Card?

Nov 14^th, 2009 at 10:09pm

Rx card

Nov 15^th, 2009 at 12:38am

Do you have multiple rx line cards? If so, did the errors propagate between the cards when the remote was trying to acquire?

Nov 15^th, 2009 at 2:34am

just one Rx line card.