Category: 3g

EEM Scripting Magic

I decided¬†¬†to use¬†cisco’s EEM Scripting Engine to activate and deactivate the cellular interface to support a Primary link failure of our MPLS Link combined with an IP SLA:

ip sla auto discovery

ip sla 100

 icmp-echo 1.1.1.1 source-interface GigabitEthernet0/1

 threshold 1000

 frequency 15

ip sla schedule 100 life forever start-time now

EEM Scripts

event manager applet Activate-3G

 event track 60 state down

¬†action 1¬† cli command “enable”

¬†action 2¬† cli command “configure terminal”

¬†action 3¬† cli command “interface cellular0/1/0”

¬†action 4¬† cli command “no shutdown”

¬†action 5¬† cli command “end”

¬†action 99 syslog msg “Primary Link Down – Activating 3G interface”

 

event manager applet Deactivate-3G

 event track 60 state up

¬†action 1¬† cli command “enable”

¬†action 2¬† cli command “configure terminal”

¬†action 3¬† cli command “interface cellular0/1/0”

¬†action 4¬† cli command “shutdown”

¬†action 5¬† cli command “end”

¬†action 99 syslog msg “Primary Link Restored – Deactivating 3G interface”

Configuring a Remote-Site Router – GSM Specific

A quick guide to setting up a GSM on a ISR using EHWIC-3G-HSPA+7.  You must get the data service account from you service provider, in turn you will receive a SIM card that you can install on to the EHWIC and an APN (Access Point Name) required to create a profile.

Insert the SIM card into the EHWIC, insert in the router and power up the device.

Chat scripts are strings fo text used to send commands for modems dialing to log in to remote systems, and to initialise asynchronous devices connected to an asynchronous line. 3G Wan interface should be treated just like any other async interface and the following chat script show the required information to connect to the GSM network, using a carrier-specific dial string and timeout value of 30 seconds.

Step 1: Create a chat script

chat-script [script-name] [script]

Example

chat-script GSM “” “AT!SCACT=1,1” TIMEOUT 30 “OK”

Step 2: Apply the chat script to the asynchronous line

line [Cellular-Interface-Number]

script dialer [Script-Name]

Example

line 0/1/0

script dialer GSM

Next, we create a GSM profile.

Step 3: From enable mode, use the profile to identify the username and password provided to you by your service provider. Use the cellular interface identifier and keyword GSM.

cellular [Cellular-Interface] gsm profile create [Sequence-Number] [AP-Name]

Tech Tip –¬†This step should be created from enable mode and not conf mode.

Example

cellular 0/1/0 gsm profile create 1 telstra.corp

Unlocking a 3G SIM while in the Router

A really useful command for unlocking the SIM while in the router.

router#sh cell 0/1/0 security
Card Holder Verification (CHV1) = Enabled
SIM Status = Locked
SIM User Operation Required = Enter CHV1
Number of Retries remaining = 3

router#cellular 0/1/0 gsm sim unlock NNNN
!!!WARNING: SIM will be unlocked with pin=NNNN(4), call will be disconnected!!!
Are you sure you want to proceed?[confirm]