我正在使用 Telit UC864-E GSM 3G 调制解调器。我想使用 pppd(ppp daemon) 在 linux 上通过 PPP 运行 GPRS/3G 连接。
我的开发板上有一个 Telit UC864-E 调制解调器，在 Atmel SAM9 微处理器上运行嵌入式 Linux。调制解调器与 SAM9 连接，我通过在 SAM9 上执行测试程序中的 AT 命令对其进行了测试。即使 GPRS/3G 使用测试应用程序也能正常工作。但是，我无法在此板上的嵌入式 linux 上通过 ppp 建立数据连接。这是日志：
# pppd call gprs
Press CTRL-C to close the connection at any stage!
defining PDP context...
AT
OK
ATZ
OK
ATE1
OK
AT+CGDCONT=1,"IP","www",,0,0
OK
Serial connection established.
using channel 1
Using interface ppp0
Connect: ppp0 <--> /dev/ttyS3
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <auth pap> <magic 0xd2b80f00> <pcomp> <]
No auth is possible
sent [LCP ConfRej id=0x1 <auth pap> <pcomp> <accomp>]
rcvd [LCP TermReq id=0x2 00 00 00 00 00 00]
sent [LCP TermAck id=0x2]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x43ee1a75>]
LCP: timeout sending Config-Requests
Connection terminated.
Modem hangup
我有一个相同调制解调器的评估板，它连接到我的运行 linux (ubuntu) 的台式 PC，我可以在其上成功运行 pppd 以访问 Internet。这是日志：
harsh@ubuntu:~$ sudo pppd call gprs
Press CTRL-C to close the connection at any stage!
defining PDP context...
AT
OK
ATZ
OK
ATE1
OK
AT+CGDCONT=1,"IP","www",,0,0
OK
Script /etc/ppp/peers/gprs-connect finished (pid 3723), status = 0x0
Serial connection established.
using channel 3
Using interface ppp0
Connect: ppp0 <--> /dev/ttyS0
Warning - secret file /etc/ppp/pap-secrets has world and/or group access
sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x8579ad41>]
rcvd [LCP ConfReq id=0x5 <asyncmap 0x0> <auth chap MD5> <magic 0xdab06202> <pcomp> <accomp>]
sent [LCP ConfRej id=0x5 <pcomp> <accomp>]
rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x8579ad41>]
rcvd [LCP ConfReq id=0x6 <asyncmap 0x0> <auth chap MD5> <magic 0xdab06202>]
sent [LCP ConfNak id=0x6 <auth pap>]
rcvd [LCP ConfReq id=0x7 <asyncmap 0x0> <auth pap> <magic 0xdab06202>]
sent [LCP ConfAck id=0x7 <asyncmap 0x0> <auth pap> <magic 0xdab06202>]
sent [LCP EchoReq id=0x0 magic=0x8579ad41]
Warning - secret file /etc/ppp/pap-secrets has world and/or group access
sent [PAP AuthReq id=0x1 user="ubuntu" password=""]
rcvd [LCP DiscReq id=0x8 magic=0xdab06202]
rcvd [PAP AuthAck id=0x1 ""]
PAP authentication succeeded
sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
rcvd [IPCP ConfNak id=0x1 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x2 <addr 0.0.0.0> <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14>]
rcvd [IPCP ConfNak id=0x2 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x3 <addr 0.0.0.0> <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14>]
rcvd [IPCP ConfNak id=0x3 <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14> <ms-wins 10.11.12.13> <ms-wins 10.11.12.14>]
sent [IPCP ConfReq id=0x4 <addr 0.0.0.0> <ms-dns1 10.11.12.13> <ms-dns2 10.11.12.14>]
rcvd [IPCP ConfReq id=0x2]
sent [IPCP ConfNak id=0x2 <addr 0.0.0.0>]
rcvd [IPCP ConfNak id=0x4 <addr 1.39.207.26> <ms-dns1 10.11.230.2> <ms-dns2 10.11.230.3>]
sent [IPCP ConfReq id=0x5 <addr 1.39.207.26> <ms-dns1 10.11.230.2> <ms-dns2 10.11.230.3>]
rcvd [IPCP ConfReq id=0x3]
sent [IPCP ConfAck id=0x3]
rcvd [IPCP ConfAck id=0x5 <addr 1.39.207.26> <ms-dns1 10.11.230.2> <ms-dns2 10.11.230.3>]
Could not determine remote IP address: defaulting to 10.64.64.64
not replacing existing default route via 192.168.170.2
Cannot determine ethernet address for proxy ARP
local IP address 1.39.207.26
remote IP address 10.64.64.64
primary DNS address 10.11.230.2
secondary DNS address 10.11.230.3
Script /etc/ppp/ip-up started (pid 3727)
Script /etc/ppp/ip-up finished (pid 3727), status = 0x0
'gprs' 脚本在两个 linux 环境中都是相同的。
可能是什么问题 ？