GPRS PPP fails to connect

[v8dave]

I am getting the following errors when trying to connect over GPRS via PPP.

The strange things is that this works on a different system with a different modem but it was tested with this modem before. I am in the process of building the second modem board to see if I get get that working instead. At least I will then have a test case to compare.

Anyway, the PPP debugging on, I get this:

Code: Select all

Prompt: Dialing server...
Setting RX ACCM:FFFFFFFF
Setting TX ACCM:FFFFFFFF
Setting RX ACCM:FFFFFFFF
Setting TX ACCM:FFFFFFFF
Wait time out
Auto baud done
Modem Reset Done
Setup String Done
connected
Starting PPP
LCP -State:STARTING
We are sending a config request with: LCP_OPT_PFC, FLAGS_RX_ACFC,
PPP TxLCP -CONF_REQid[00][ 07020802
LCP -State:REQ_SENT
IPCP-State:STARTING
PPP RxLCP -CONF_REJid[00][ 07020802
We received a config NAC for:
LCP_OPT_PFC
LCP_OPT_ACFC
We are sending a config request with:
PPP TxLCP -CONF_REQid[01][
PPP RxLCP -CONF_REQid[01][ 0206000000000304C0230506B9EF7900
LCP_OPT_ACCM read 0 - BAD(NAC) we ask for  4294967295
LCP_OPT_AUTH read 0xC023 - GOOD(ACK), they want PAP
LCP_OPT_MAGIC read and is GOOD(ACK)
PPP TxLCP -CONF_NAKid[01][ 0206FFFFFFFF
PPP RxLCP -CONF_ACKid[01][
LCP -State:ACK_RX
PPP RxLCP -CONF_REQid[02][ 0206FFFFFFFF0304C023050615F07900
LCP_OPT_ACCM read 4294967295 - GOOD(ACK)
LCP_OPT_AUTH read 0xC023 - GOOD(ACK), they want PAP
LCP_OPT_MAGIC read and is GOOD(ACK)
PPP TxLCP -CONF_ACKid[02][ 0206FFFFFFFF0304C023050615F07900
LCP -State:Authenticating
Setting RX ACCM:FFFFFFFF
Setting RX ACCM:FFFFFFFF
Setting TX ACCM:FFFFFFFF
Sent PAP request
Sending PAP packet
PPP TxPAP -CONF_REQid[03][ 0377617009776170313233202020
PPP RxPAP -CONF_ACKid[03][ 0857656C636F6D6521
Setting RX ACCM:FFFFFFFF
Setting RX ACCM:FFFFFFFF
Setting TX ACCM:FFFFFFFF
LCP -State:OPENED
PPP TxIPCP-CONF_REQid[03][ 0306000000000206002D0F00810600000000830600000000
IPCP-State:REQ_SENT
PPP RxIPCP-CONF_REQid[02][ 0306C0A8CA00
PPP TxIPCP-CONF_ACKid[02][ 0306C0A8CA00
IPCP-State:ACK_SENT
PPP RxIPCP-CONF_REJid[03][ 0206002D0F00830600000000
PPP TxIPCP-CONF_REQid[04][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[04][ 830600000000
PPP TxIPCP-CONF_REQid[05][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[05][ 830600000000
PPP TxIPCP-CONF_REQid[06][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[06][ 830600000000
PPP TxIPCP-CONF_REQid[07][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[07][ 830600000000
PPP TxIPCP-CONF_REQid[08][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[08][ 830600000000
PPP TxIPCP-CONF_REQid[09][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[09][ 830600000000
PPP TxIPCP-CONF_REQid[0A][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0A][ 830600000000
PPP TxIPCP-CONF_REQid[0B][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0B][ 830600000000
PPP TxIPCP-CONF_REQid[0C][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0C][ 830600000000
PPP TxIPCP-CONF_REQid[0D][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0D][ 830600000000
PPP TxIPCP-CONF_REQid[0E][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0E][ 830600000000
PPP TxIPCP-CONF_REQid[0F][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[0F][ 830600000000
PPP TxIPCP-CONF_REQid[10][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[10][ 830600000000
PPP TxIPCP-CONF_REQid[11][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[11][ 830600000000
PPP TxIPCP-CONF_REQid[12][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[12][ 830600000000
PPP TxIPCP-CONF_REQid[13][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[13][ 830600000000
PPP TxIPCP-CONF_REQid[14][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[14][ 830600000000
PPP TxIPCP-CONF_REQid[15][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[15][ 830600000000
PPP TxIPCP-CONF_REQid[16][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[16][ 830600000000
PPP TxIPCP-CONF_REQid[17][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[17][ 830600000000
PPP TxIPCP-CONF_REQid[18][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[18][ 830600000000
PPP TxIPCP-CONF_REQid[19][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[19][ 830600000000
PPP TxIPCP-CONF_REQid[1A][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1A][ 830600000000
PPP TxIPCP-CONF_REQid[1B][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1B][ 830600000000
PPP TxIPCP-CONF_REQid[1C][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1C][ 830600000000
PPP TxIPCP-CONF_REQid[1D][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1D][ 830600000000
PPP TxIPCP-CONF_REQid[1E][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1E][ 830600000000
PPP TxIPCP-CONF_REQid[1F][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[1F][ 830600000000
PPP TxIPCP-CONF_REQid[20][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[20][ 830600000000
PPP TxIPCP-CONF_REQid[21][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[21][ 830600000000
PPP TxIPCP-CONF_REQid[22][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[22][ 830600000000
PPP TxIPCP-CONF_REQid[23][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[23][ 830600000000
PPP TxIPCP-CONF_REQid[24][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[24][ 830600000000
PPP TxIPCP-CONF_REQid[25][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REQid[02][ 0306B600C50D
PPP TxIPCP-CONF_NAKid[02][ 0306C0A8CA00
IPCP-State:REQ_SENT
PPP TxLCP -TERM_REQid[26][
LCP -State:CLOSING
PPP TxIPCP-CONF_REQid[27][ 030600000000810600000000830600000000
PPP TxIPCP-CONF_NAKid[02][ 0306C0A8CA00
IPCP-State:REQ_SENT
PPP RxIPCP-CONF_REJid[25][ 830600000000
Got NAK For wrong seq
PPP RxIPCP-CONF_REQid[03][ 0306C0A8CA00
PPP TxIPCP-CONF_ACKid[03][ 0306C0A8CA00
IPCP-State:ACK_SENT
PPP RxLCP -TERM_ACKid[26][
LCP -State:CLOSED

I am trying to figure out where the IP address (C0A8CA00) (192.168.202.0) is coming from in the packet above. This does not appear to be a valid IP from the ISP (Telkomsel, Indonesia)

Any pointers would be appreciated?

Dave...

[v8dave]

Hi All,

Further testing today.

In the above were it negotiate the PAP authentication, I can see that it send the username and password

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PPP TxPAP -CONF_REQid[03][ 0377617009776170313233202020

And then gets back a reply (Welcome!)

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PPP RxPAP -CONF_ACKid[03][ 0857656C636F6D6521

The next bit is the receiving of the IP address

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PPP RxIPCP-CONF_REQid[02][ 0306C0A8CA00

Followed by and ACK from the Netburner.

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PPP TxIPCP-CONF_ACKid[02][ 0306C0A8CA00

The next part I am not sure what is being passed and I am still trying to work out what is failing, but sometimes this goes back and forth for about 10-20 times before it fails and drops the connection.

Code: Select all

PPP RxIPCP-CONF_REJid[03][ 0206002D0F00830600000000
PPP TxIPCP-CONF_REQid[04][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[04][ 830600000000
PPP TxIPCP-CONF_REQid[05][ 030600000000810600000000830600000000
PPP RxIPCP-CONF_REJid[05][ 830600000000
PPP TxIPCP-CONF_REQid[06][ 030600000000810600000000830600000000

The 83 in the above is a NAK reply to the 03.

I need to work out what the 02 is from the ISP end. It seems to be that the Netburner sends back ALL ZEROS for the IP address and I need to work out why.

Cheers
Dave....

[rnixon]

Hi Dave, I's been a lot of years since I looked at PPP, but I think there are LCP (Link Control Protocol) and NCP (Network Control Protocol) options that get negotiated. Some are optional and some can be made mandatory. Both devices send which options the require/support back and forth. I looked in my (ancient) PPP Design and Debugging book by James Carlson and can see an IPCP option 03: If the address is 00 00 00 00, the peer is requested to send a config-nak specifying the address of the local system, perhaps by looking up the authenticated peer name from PAP in a database. If this fails, the IPCP protocol should be shut down with a protocol reject.

That last text was from the book, and I don't know enough low level detail to interpret it, but it seems to fit your description. It also mentions RFC 1332. It might be that the nb is asking to be given an IP address. If you set a static one, how would you know if it was on the same subnet as the modem?

[Vernon]

Did you pay the bill ?

[v8dave]

Hi Vernon and all,

(cross posted from another issue I had)

I got it working. Looking at the debug output I saw that the ISP was rejecting the secondary DNS configuration request.

I decided to disable this in the request and hey presto the ISP connected first time.


The PPP code needs a bit of work as the primary DNS is not actually set in the recent release.

I'll tidy up my code changes to PPP and send this to Netburner shortly as it may help others who are having the same issues.

If anyone wants the code changes here let me know and I'll post them with details.

Dave...