Whispers & Screams
And Other Things

Configuring 3G Wireless WAN on Modular and Fixed ISRs (HWIC-3G-GSM, HWIC-3G-HSPA, PCEX-3G-HSPA-x)


Cisco Integrated Services Routers are branch routers which support the new paradigms of network traffic delivery in the cloud and on the move. They provide Internet connectivity to teleworkers, and minor sites supporting less than 20 users. They also support bridging and routing between the LAN and the WAN whilst providing many advanced features such as antivirus protection.


The Third Generation (3G) Wireless High-Speed WAN Interface Card (HWIC) is a multiband, multiservice WAN card for use over WCDMA Radio Access Networks (RAN).


Both the fixed and the modular 3G routers can be used as the primary WAN connectivity and as a backup for critical applications which require a fallback service. 3G WAN is supported on the following modular Cisco ISRs: 800, 1841, 1861, 2800 series, 3800 series, 1900, 2900 and 3900.


One of the first actions required will be to configure a new 3G HWIC data profile.


To configure your 3G HWIC data profile, you will need the following information from your service provider:


Username (if required by your carrier)


Password (if required by your carrier)


Access Point Name (APN)


Once obtained, we can begin to set up the 3G features on the equipment itself by following these procedures:

    1. Data Account Provisioning


    1. Data Call Setup


    1. Voice Initiated Data Callback or Remote Dial-in (Optional)

In order to provision our data account we must have first obtained the key information from the service provider. The next priority is to ensure that we have the necessary service availability and signal strength in order for the connection to work. We need to use the following commands to examine the services available on the 3G network at the location in question.

    1. show cellular network - This displays info about the carrier network.


    1. show cellular radio - This shows the signal strength. We are looking for RSSI of -90dBm for a steady and reliable connection.


    1. show cellular security - This shows SIM lock status and modem lock status.

Once we have determined that the conditions are favourable we can go ahead and set up a modem data profile. To examine the existing data profiles configured on the equipment use the command show cellular profile. 

Assuming the profile we need is not already created we will need to go ahead and create it. In order to do this we use the command cellular gsm profile create . The syntax required is as follows:

cellular <slot/wic/port> gsm profile create <profile number> <apn> <authentication> <username> <password>

for example

cellular 0/0/0 gsm profile create 1 vodafone.apn chap 3guser 3guserpass

The data profile parameters are as follows:

    • apn - Access Point Name - This must be obtained from the service provider


    • authentication - Usually chap or pap


    • username - provided by service provider


    • password - provided by service provider

Once the data profile is properly set we then look to set up the parameters for the correct operation of the data call.

Firstly it is necessary to configure the cellular interface. The steps in summary are as follows:

1. configure terminal


2. interface cellular <slot/wic/port>


3. encapsulation ppp


4. ppp chap hostname <host>


5. ppp chap password 0 <password>


6. asynchronous mode interactive


7. ip address negotiated


The authentication parameters used here must be the same as those configured under the earlier GSM profile.


Once this is configured we need only configure the dialer and the steps for doing this in summary are as follows:


1. configure terminal


2. interface cellular <slot/wic/port>


3. dialer in-band


4. dialer idle-timeout <seconds>


5. dialer string <string>


6. dialer group <number>


7. exit


8. dialer-list <dialer-group> protocol <protocol-name> {permit | deny | list <access-list-number> | access-group}>


9. ip access-list<access list number>permit <ip source address>


10. line <slot/wic/port>


11. script dialer <regexp>


12. exit


13. chat-script <script name> "" "ATDT*98*<profile number>#" TIMEOUT <timeout value> CONNECT


14. interface cellular <slot/wic/port>


So that should be it. Assuming the router is properly configured elsewhere, the traffic should begin to flow using the 3G interface and everything should be working just fine. Of course sometimes things dont work out quite so smoothly and I will publish a post soon detailing the steps needed to troubleshoot these types of connections when they dont work as planned.


I hope this summary is useful and would appreciate your comments using the form provided below.

The Chirpsounder / Ionosonde
Cisco Open SOC

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