Re: [Freeswitch-users] Outgoing calls from unknown users

Re: [Freeswitch-users] Outgoing calls from unknown users If you were seeing a billtime of 0 that means the calls were blocked... Some one was probably hitting the “external” interface then hitting the public context... This is allowed in the default example configs for freeswitch, but calls coming in that way are only allowed to actually do something if a) they hit one of the pre-defined local extensions or you have modified it to allow other calling.

Why is it like this? This is so you can define your local extensions and DIDs in the public context then say hey you can just call me via sip to SIP:mynumber_or_extension@hostname.or.ip.of.my.FS.box.com

Bots will scan the internet (the entire internet) and find your public profile is not doing sip challenge response, then they will try to place calls. In your logs they were trying to call a number in what appears to be Palestine, this is very comon, as they are probing to see if you let the calls pass by trying various prefixes...

As long as you are configuring the unauthenticated interfaces to only allow calls for your local extensions this is not a big dead, they will give up and go away.

On 2/22/13 9:48 AM, "Frederick Pruneau" <frederick@targointernet.com> wrote:

PB 20618

Everytime, it is a 0 billsec. For now, international calls are not authorized. But in a near future, I want to authorized them.

I verified what Ken wrote:

A) make sure you are not using the default username and passwords for
registered sip users (not using default username and password. All default users/extensions have been removed)
B) don't allow unauthenticated calls to go back out to the PSTN (I don't have PSTN lines)
C) Use appropriate firewall rules to only allow places you should be getting
calls from (Already done)
D) use something like Fail2Ban to block people attempting to make repeated
failed calls/registration attempts in a short period of time...

Actually, I have fail2ban that blocks registration attemps. I don't know how to block failed calls. Can you guide me to a web site or help me to ban failed calls?

Thank you for your quick replies!

Fred

Le 2013-02-22 09:01, Christian Benke a écrit :

Do you have a logfile of these calls? Can you please paste it to
http://pastebin.freeswitch.org/. Otherwise, please paste your
dialplans to pastebin so we can figure out what's really happening
with your calls, the csv has too little information. Do all of these
calls have 0 billsec?

If possible, you should turn off FreeSWITCH till you know the reason
for this calls, it looks very much like your system is not safe.

Best regards,
Christian

--
Central Asia by bike, starting May 2013 - http://poab.org

On 22 February 2013 14:26, Frederick Pruneau
<frederick@targointernet.com> <mailto:frederick@targointernet.com> wrote:

Hi everyone!

I have found in the log files some international calls from unknown
extensions. These extensions don't exist in my configuration. I tried to
block them in my firewall (iptables on my freeswitch server) but they
always use random IP adresses. Here is a short part of my Master.csv:

"1001","1001","0015972595646444","2013-02-22 02:05:27","","2013-02-22
02:05:27","0","NORMAL_CLEARING","3c876eae-7cbe-11e2-877f-b791adff5763","","","",""
"1001","1001","9011972595646444","2013-02-22 02:05:28","","2013-02-22
02:05:28","0","NORMAL_CLEARING","3d0d058c-7cbe-11e2-8783-b791adff5763","","","",""
"1001","1001","2011972595646444","2013-02-22 02:05:29","","2013-02-22
02:05:29","0","NORMAL_CLEARING","3da55576-7cbe-11e2-8787-b791adff5763","","","",""
"1001","1001","3011972595646444","2013-02-22 02:05:30","","2013-02-22
02:05:30","0","NORMAL_CLEARING","3e4727ca-7cbe-11e2-878b-b791adff5763","","","",""
"1001","1001","4011972595646444","2013-02-22 02:05:31","","2013-02-22
02:05:31","0","NORMAL_CLEARING","3eecc2e8-7cbe-11e2-878f-b791adff5763","","","",""
"1001","1001","5011972595646444","2013-02-22 02:05:32","","2013-02-22
02:05:32","0","NORMAL_CLEARING","3f633b94-7cbe-11e2-8793-b791adff5763","","","",""
"1001","1001","6011972595646444","2013-02-22 02:05:33","","2013-02-22
02:05:33","0","NORMAL_CLEARING","3fc49902-7cbe-11e2-8797-b791adff5763","","","",""
"1001","1001","7011972595646444","2013-02-22 02:05:33","","2013-02-22
02:05:33","0","NORMAL_CLEARING","403c0622-7cbe-11e2-879b-b791adff5763","","","",""
"1001","1001","8011972595646444","2013-02-22 02:05:34","","2013-02-22
02:05:34","0","NORMAL_CLEARING","40e61ef0-7cbe-11e2-879f-b791adff5763","","","",""

With my configuration, I need to be registered to make a call. I tried
to call with an unregistered phone and I was not able to make a call. I
don't know how they are able to do this but I need to block them. Is
there something that I am missing in my configuration to block unwanted
extensions to make calls?

Thanks in advance!

Fred

_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org

_________________________________________________________________________
Professional FreeSWITCH Consulting Services:
consulting@freeswitch.org
http://www.freeswitchsolutions.com

FreeSWITCH-powered IP PBX: The CudaTel Communication Server
http://www.cudatel.com

Official FreeSWITCH Sites
http://www.freeswitch.org
http://wiki.freeswitch.org
http://www.cluecon.com

FreeSWITCH-users mailing list
FreeSWITCH-users@lists.freeswitch.org
http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
http://www.freeswitch.org

--
Ken
http://www.FreeSWITCH.org
http://www.ClueCon.com
http://www.OSTAG.org
irc.freenode.net #freeswitch