I get really poor signal with TMo and Sprint in my area, but I am using Project Fi for my cellular service. I figured I’d grab one of their free SIMs and put my HWIC-3G-GSM back in service. Unfortunately.. I get really poor signal. Like -102dB RSSI! I’m going to have to see if I can get a cheap TNC antenna with a cord long enough to put it outside; for some reason I can get good signal according to my Nexus 5X — even getting LTE just by stepping outside.

For now I figured I’d get the basic configuration done. Even with little to go by it was fairly easy to setup — especially as most cell carriers don’t have PAP/CHAP authentication.



router(config)#
chat-script gsm "" "ATDT*99#" TIMEOUT 30 CONNECT
!
interface Cellular0/0/0
 description Project Fi - TMobile
 ip address negotiated
 ip nat outside
 ip virtual-reassembly in
 encapsulation ppp
 dialer in-band
 dialer idle-timeout 360 either
 dialer string GSM
 dialer-group 1
 async mode interactive
 ppp chap hostname h2g2
 ppp chap password 0 ""
 ppp ipcp dns request
!
ip nat inside source list 1 interface Cellular0/0/0 overload
ip route 0.0.0.0 0.0.0.0 Cellular0/0/0
!
access-list 1 permit any
dialer-list 1 protocol ip list 1
!
line 0/0/0
 script dialer GSM
 modem InOut
 no exec
 rxspeed 3600000
 txspeed 384000
!
^Z


router#cellular 0/0/0 gsm profile create 1 h2g2 



Note that you can also pass authentication information in the GSM profile creation; however that isn’t needed for Project Fi.


This was a basic test just to see if I could get connectivity, I’m going to use it as an alternate route to the big cloud that is the internet in the event that I really need access and Time Warner Cable has let me down by abusing maintenance windows daily — as seems to be the case lately!


So far I’ve run into issues; I’d disconnect from the network and not be able to reconnect. Sometimes a modem power-cycle fixes this. I decided to upgrade the crusty old firmware to something slightly less crusty (note: I hate Sierra Wireless modems) — Cisco says “not for use in the US,” however it IS listed for the MC8775 modem on my HWIC and I know people have used it for the same modem in ThinkPads (trusty T61/T61p!) in the US. I couldn’t get it through Cisco as you need a support contract for Sierra Wireless firmware, oddly enough. I was able to find it online, you’d be looking for version 2.0.8.19 — generally named 8775_h2_0_8_19.tar. This of course will depend on the modem in your HWIC as they didn’t all come with MC8775s.


Check your hardware! It’s easy enough to see what modem is on your HWIC even if you don’t want to physically pull it to check it:


cell.wan#sh controllers cellular 0/0/0


Interface Cellular0/0/0
HSDPA/UMTS/EDGE/GPRS-850/900/1800/1900/2100MHz unit 0, 
HWIC cellular modem configuration:
---------------------------


Modem is recognized as valid for this HWIC
manufacture id: 0x00001199 product id: 0x00006812
Sierra Wireless MC8775 UMTS modem.
GPS State: GPS disabled


Pre-upgrade:


cell.wan#sh cell 0/0/0 hardware
Modem Firmware Version = H1_1_8_3MCAP C:/WS/F
Modem Firmware built = 03/08/07
Hardware Version = 1.0
International Mobile Subscriber Identity (IMSI) = NUMBERSHERE
International Mobile Equipment Identity (IMEI) = NUMBERSHERE
Integrated Circuit Card ID (ICCID) = NUMBERSHERE
Mobile Subscriber International Subscriber
IDentity Number (MSISDN) = NUMBERSHERE
Factory Serial Number (FSN) = NUMBERSHERE
Modem Status = Low Power Mode
Current Modem Temperature = 23 deg C, State = Normal
PRI SKU ID = 0, SKU Rev. = 20.0


Upgrade process:


cell.wan#microcode reload cellular 0 0 gsm modem-provision
Reload microcode? [confirm]
Log status of firmware download in router flash?[confirm]
Firmware download status will be logged in flash:fwlogfile
Microcode Reload Process launched for hwic slot=0; hw type=0x51E
cell.wan#
*****************************************************
 The interface will be Shut Down for Firmware Upgrade 
 This will terminate any active data connections.
 Do not make any config changes related to the interface.
*****************************************************
Modem radio has been turned off
*****************************************************
 Modem will be upgraded!
 Upgrade process will take up to 15 minutes. During 
 this time the modem will be unusable.
 Please do not remove power or reload the router during 
 the upgrade process.
*****************************************************
backing up NV data..Could take up to 3 minutes


*Aug 23 10:18:06.423: %LINK-5-CHANGED: Interface Cellular0/0/0, changed state to administratively down++++++++++++++++++++++++++++++
Prepare modem for downloading boot image.
Begin boot image download
Firmware [size:234279 bytes] will be downloaded in 228 segments


Sync indication Successful
Sync indication Successful
***** Boot File Upgrade OK *****


******************************************
The firmware file will be copied in blocks 
from Compact Flash. Please DO NOT remove 
Compact Flash during Upgrade Process. Doing 
so will cause download failure and leave 
modem in unusable state
*******************************************
Begin application image download
Firmware [size:13393280 bytes] will be downloaded in 13129 segments
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Sync indication Successful
Sync indication Successful
***** Application Firmware Upgrade OK *****


Modem Upgrade OK
*Aug 23 10:25:30.179: %CELLWAN-2-MODEM_DOWN: Modem in HWIC slot 0/0 is DOWN
*Aug 23 10:25:46.963: %CELLWAN-2-MODEM_UP: Modem in HWIC slot 0/0 is now UP
*Aug 23 10:25:46.963: %CELLWAN-2-MODEM_DOWN: Modem in HWIC slot 0/0 is DOWN
*Aug 23 10:26:00.191: %CELLWAN-2-MODEM_UP: Modem in HWIC slot 0/0 is now UP
Modem radio has been turned on
*Aug 23 10:26:44.587: %LINK-3-UPDOWN: Interface Cellular0/0/0, changed state to down


Post-upgrade:


cell.wan#sh cellular 0/0/0 hardware
Modem Firmware Version = H2_0_8_19MCAP G:/WS/
Modem Firmware built = 08/29/08
Hardware Version = 1.0
International Mobile Subscriber Identity (IMSI) = NUMBERSHERE
International Mobile Equipment Identity (IMEI) = NUMBERSHERE
Integrated Circuit Card ID (ICCID) = NUMBERSHERE
Mobile Subscriber International Subscriber
IDentity Number (MSISDN) = NUMBERSHERE
Factory Serial Number (FSN) = NUMBERSHERE
Modem Status = Online
Current Modem Temperature = 27 deg C, State = Normal
PRI SKU ID = 9991803, SKU Rev. = 1.3




The 2.0.8 line increases the HSDPA downlink speed from 3.6mbit/s to 7.2mbit/s (assuming your signal is acceptable, of course). I’m just hoping it stabilizes my connection and I don’t have to do any actual debugging! After installing the firmware update I had no problems bringing a connection up. So far it seems “more stable,” but only time will tell if it randomly drops. It also gives more information from “show cellular 0/0/0” ..


Once I get an antenna and (hopefully) better signal so I can maintain “usable,” speeds for basic browsing I’ll throw it in the routing table. For now, it can sit to the side as a novelty.