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Sanyo RL-4920 and the Penguin

Here's how to use the Sprint PCS Vision service with your RL-4920 phone to get online anywhere you have Sprint service. You will need a USB data cable for your phone. I am using the cable I originally bought for my Sanyo 4900. It's still compatible and I picked it up at Radio Shack. I'm sure you can find them online at varios retailers or on eBay for cheap.

To start, you need have USB Modem (CDC ACM) support in your kernel or loaded as a module. I'm using 2.6.14-gentoo-r2, but this driver exists even in the 2.4 branch.

In your kernel .config:

     CONFIG_USB_ACM=y

     Device Drivers -> USB Support -> USB Device Class driver -- USB Modem (CDC ACM) support

     usb 1-2: new full speed USB device using uhci_hcd and address 2
     cdc_acm 1-2:1.0: ttyACM0: USB ACM device

I used Wv Dial to setup my PPP link for me. The included program wvdialconf created a basic config file for me automagically which I tweeked a little bit to make it work right.

My wvdial.conf:

[Dialer Defaults]
Modem = /dev/ttyACM0
Baud = 460800
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ISDN = 0
Modem Type = USB Modem
Phone = #777
Username = ''
Password = ''
Carrier Check = no
Stupid Mode = yes

# wvdial --> WvDial: Internet dialer version 1.54.0 --> Initializing modem. --> Sending: ATZ ATZ OK --> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 OK --> Modem initialized. --> Sending: ATDT#777 --> Waiting for carrier. ATDT#777 CONNECT ~[7f]}#@!}!}4} }8}!}$}%j}"}&} } } } }%}&}&}7=1}'}"}(}"zZ~ --> Carrier detected. Starting PPP immediately. --> Starting pppd at Wed Nov 30 12:21:20 2005 --> pid of pppd: 14223 --> Using interface ppp0 --> local IP address 68.246.198.foo --> remote IP address 68.28.97.foo --> primary DNS address 68.28.122.foo --> secondary DNS address 68.28.114.foo

Notes: DNS servers are detected automatically. IPs masked to protect the innocent.

I get a 128kbps downlink (16KBps), with decent latencies (350ms - 600ms). The connection sometimes hangs without warning, and I'll have to restart wvdial. I think this is due to wireless signal quality. I pay an extra $10 for unlimited Vision service, putting my bill around $40 for a decent minute plan and internet.

The sprint gateway recompresses all JPEGS down into the noticable artifacting range. This is done transparently as there are no proxies involved. To avoid this issue, I use OpenVPN to tunnel all my traffic back to my home LAN which is connected to the internet via Comcast cable. OpenSSH can create nice secure tunnels for you as well. This will have the benefit of an encrypted session and Sprint will be unable to alter anything in your browsing session. While the phone has a data connection and a power connection, you can't use both at the same time. It's not a technical issue, just one of physical space:

I haven't looked into whether anyone makes a special cable (I doubt it), but the battery life on this phone is excellent, so it hasn't been a problem.

Here's my nmap run done from my cable connection against the Sprint connection. I had no iptables rules and only sshd was running. They filter a surprising number of ports as well as ICMP.

# nmap -P0 68.246.116.foo

Starting nmap 3.75 ( http://www.insecure.org/nmap/ ) at 2005-11-30 16:53 EST
Interesting ports on foo.area3.spcsdns.net (68.246.116.foo):
(The 1640 ports scanned but not shown below are in state: closed)
PORT      STATE    SERVICE
22/tcp    open     ssh
80/tcp    filtered http
113/tcp   filtered auth
135/tcp   filtered msrpc
136/tcp   filtered profile
137/tcp   filtered netbios-ns
138/tcp   filtered netbios-dgm
139/tcp   filtered netbios-ssn
445/tcp   filtered microsoft-ds
559/tcp   filtered teedtap
901/tcp   filtered samba-swat
1022/tcp  filtered unknown
1023/tcp  filtered netvenuechat
1025/tcp  filtered NFS-or-IIS
1433/tcp  filtered ms-sql-s
3128/tcp  filtered squid-http
3306/tcp  filtered mysql
4000/tcp  filtered remoteanything
4899/tcp  filtered radmin
5000/tcp  filtered UPnP
17300/tcp filtered kuang2
27374/tcp filtered subseven

Nmap run completed -- 1 IP address (1 host up) scanned in 111.235 seconds

BitPim works great for my phonebook. I'm using version 0.7.34. Just point it to /dev/ttyACM0. I haven't tried any ringers yet, I'm not sure what format the phone needs, but wallpaper in JPEG works fine.