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Problem with 3G dial - 881G PCEX-HSPA-G

Hey Guys..

Can you tell me if the router automatically connects to internet even if you dont do a ping test?

I have configured a 881G with PCEX-HSPA-G module and the Cellular interface never comes up untill I ping any internet IP from the router CLI.

Is there any configuration I need which will make the Cellular interface to come up as soon as the router is reloaded.

I have attached my current config. Please help as I need to run a VPN tunnel on this.

Note : By cellular interface coming Up, I meant that Amber LED on the module will continously blinkin which indicates that the connection has not been established. Once I do a ping test from the router console, the LED becomes stable which shows that the connection is up and running,

1 ACCEPTED SOLUTION

Accepted Solutions
Silver

Problem with 3G dial - 881G PCEX-HSPA-G

Hi Arjun,

you can configure "Dialer persistent" under the dialer interface. That will bring up the link as soon as the router is reloaded, even if there is no interesting traffic.

To configure it, you need to create a dialer interface over the cellular.

For example:

interface Cellular0

no ip address

ip virtual-reassembly

encapsulation ppp

dialer in-band

dialer-group 1              

dialer pool-member 1             >>>> associate with the dialer 1 interface.

async mode interactive

interface Dialer1

ip address negotiated

encapsulation ppp

dialer pool 1                        >>>> define the dialer pool

dialer string gsm

dialer persistent           <<<<<<

All additional features (PPP, NAT etc.) should be applied to the dialer interface.

In alternative, you can use IP SLA to ping a public IP at regular intervals.

Cheers

Marco

5 REPLIES
Silver

Problem with 3G dial - 881G PCEX-HSPA-G

Hi Arjun,

you can configure "Dialer persistent" under the dialer interface. That will bring up the link as soon as the router is reloaded, even if there is no interesting traffic.

To configure it, you need to create a dialer interface over the cellular.

For example:

interface Cellular0

no ip address

ip virtual-reassembly

encapsulation ppp

dialer in-band

dialer-group 1              

dialer pool-member 1             >>>> associate with the dialer 1 interface.

async mode interactive

interface Dialer1

ip address negotiated

encapsulation ppp

dialer pool 1                        >>>> define the dialer pool

dialer string gsm

dialer persistent           <<<<<<

All additional features (PPP, NAT etc.) should be applied to the dialer interface.

In alternative, you can use IP SLA to ping a public IP at regular intervals.

Cheers

Marco

New Member

Problem with 3G dial - 881G PCEX-HSPA-G

Hey Marco.. Thanks again.

What about the configuration for Line 3 interface and Chat-script.. That remains the same as I have configured in the Config file is it??

If yes, Why is the dialer and Line 3 both configs needed?

Silver

Problem with 3G dial - 881G PCEX-HSPA-G

Line 3 will remain the same. Line 3 is used for communication between IOS and the modem itself.

So, usually you need the config on line 3 (to communicate with the modem) and the interface cellular (to add all IOS features, like IP address and NAT).

The cellular interface behaves like a dialer interface. However, not all dialer commands can be applied there.

For this reason, whenever needed we configure a dialer interface over the cellular.

Cheers

Marco

** Remember to rate posts when they are useful **

New Member

Re: Problem with 3G dial - 881G PCEX-HSPA-G

Ok, great. But How is that I was able to connect with out the dialer interface in the previous config I have attached?

Arjun

Silver

Re: Problem with 3G dial - 881G PCEX-HSPA-G

> Ok, great. But How is that I was able to connect with out the dialer interface in the previous config I have attached?

Arjun, the configuration you had before is correct and  valid. It will work normally. However, if you want to configure dialer  persistent, you need to have a dialer interface over the cellular.

If you don't want to use dialer persistent then you can remove the dialer and go back to the previous configuration.

From  the logical point of view, using only the cellular interface, or using  the dialer over the cellular will not make any difference.

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