[asterisk-users] Which router/firewall would you use for a virtual-PBX Asterisk installation?

Telium Technical Support support at telium.ca
Mon Nov 23 14:02:52 CST 2015


If you are focused on routing, we've used 4 Cisco SG300-28p in router mode -
economical way to handle vlans etc for ~100 POE phone sets,  (with GB
interconnects).  At the edge Cisco ASA-55xx work well, and we've done a few
deployments with Mikrotik routers that are quite inexpensive and performed
impresively for their cost.

>From a security standpoint, consider what happened last summer when hackers
found an exploit in the FreePBX web interface.  They rewrote the PBX
dialplan, disabled CDR's, and made unlimited calls to premium rate numbers.
This was a real wakeup call for FreePBX users who though Fail2Ban was a
security system, or CDR's could be used to catch compromised accounts.
Digium warns everyone that fail2ban is not a security system:
http://forums.asterisk.org/viewtopic.php?p=159984

If you don't want a security system on your PBX, see if your ITSP will limit
your account to $X/day, restrict routes, etc.  

There are also some great Astricon videos online where they invite speakers
to talk about security.  You'll see that fail2ban + A2Billing doesn't keep
out anyone except the script kiddies.



-----Original Message-----
From: asterisk-users-bounces at lists.digium.com
[mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Ernie Dunbar
Sent: Monday, November 23, 2015 2:17 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Which router/firewall would you use for a
virtual-PBX Asterisk installation?

Oh, don't worry about us going cheap on security. We use A2Billing 
(along with some Fail2Ban configuration for bad logins) to limit the 
number and cost of calls that can go out through a compromised SIP 
account, so that when, not *if*,  a customer's SIP account gets 
compromised, the attacker gets cut off at the knees before they can even 
get out the door. We've even added bogus connection charges on 
international calls that get removed before we bill our customers, to 
speed up the process and reduce our losses even further. Our customers 
are even happy that these billing limits are in place.

No, this is all about playing nice with our load balancing software and 
protecting databases and backend servers that have no business being 
available to the public. But mostly it's about the load balancer 
(IPTables on said servers can take care of "visible to the public). I 
just want to make sure that the router we use will play nice with 
Asterisk, since we've already seen network hardware that looks good on 
paper, but fails miserably in practice. In fact, we see it so often with 
individual customers' crap routers causing voice quality issues, that by 
default we don't trust simple math.

So here I am, asking everyone what router they use, and whether you're 
happy with the results when there's 100 simultaneous SIP calls in 
progress. I want to know what happens when the rubber hits the road.

On 2015-11-20 14:22, Telium Technical Support wrote:
> Well router and firewall are very different...it depends on what you 
> are
> trying to accomplish.
> 
> If you are trying to secure an Asterisk-based call center, get a real
> security product.  Look here for details:
> http://www.voip-info.org/wiki/view/Asterisk+security
> 
> This covers firewall, Asterisk lock-down, and Asterisk specific 
> security.
> The average break-in/fraud cost is $25,000 per day.  (watch the 
> Astricon
> videos for more details).  So going cheap on security isn't a smart 
> move for
> a commercial installation.
> 
> If you just want a router/switch, figure out the simultaneous call 
> capacity
> x codec demands in bps, and there is your backplane switching speed
> requirements.  Even with 100 simultaneous calls at g711, a lower end 
> Cisco
> (3xx) router/switch will have no problem.
> 
> -M-
> 
> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com
> [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Ernie 
> Dunbar
> Sent: Friday, November 20, 2015 3:25 PM
> To: Asterisk Users
> Subject: [asterisk-users] Which router/firewall would you use for a
> virtual-PBX Asterisk installation?
> 
> Hi everyone.
> 
> We've got a fairly large base of customers who use our Asterisk server
> for phone service in a virtual PBX kind of way, where the server is
> security hardened and exposed to the internet for them to connect to
> remotely with SIP and IAX. It's certainly not the sort of affair where
> we're running it as a PBX just within the building. As a result, we see
> network traffic coming through eth0 between 512 Kbps and about 3.0 
> Mbps,
> depending on the time of day.
> 
> We haven't so far been using a hardware firewall/router on our server
> network, but it's becoming increasingly clear that we need to. We have
> enough experience to know that Asterisk is pretty sensitive when it
> comes to network hardware in our situation - we've had to replace one
> otherwise perfectly good 100 Mbps network switch because it simply
> wasn't able to keep up with the amount of streaming audio we put 
> through
> it, and it badly affected voice quality. We have other traffic flowing
> through our server network too, including a significant amount of 
> e-mail
> and web traffic, although that's not quite as sensitive to the quality
> of our network hardware.
> 
> If you've got these large requirements for Asterisk, I'd love to hear
> what you use for a router, and whether that router has met your needs.
> It would also be nice to hear about what kinds of routers to avoid that
> you may have tried in the past and found lacking.
> 
> --
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