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connecting two adsl circuits to the 3cx ?

Discussion in '3CX Phone System - General' started by htcomm, Jul 10, 2009.

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  1. htcomm

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    Hello

    We intend to use the 3CX with a sip trunk over an adsl circuit. However I don't think the bandwidth will be sufficient.

    Is there a way with the 3CX that we can connect two adsl circuits and route outgoing calls exclusively through one of these adsl circuits ?

    Thanks, htcomm
     
  2. Nick Galea

    Nick Galea Site Admin

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    This has to be done at network level, its not related to 3CX....
     
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  3. leejor

    leejor Well-Known Member

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    There are routers that will take more than one Ethernet WAN connection to allow bandwidth sharing. You'd have to do a search on the net for them......

    Here is a link to one multi WAN router, I'm sure that there are a number more. http://www.peplink.com/
     
  4. thenua

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    I run two Internet connections. One Cable (with average bandwidth) and one ADSL (with fairly good bandwidth). In my case, I ensure 3CX goes to the Internet via the ADSL connection.

    As Nick (Admin) said, its a networking problem not a 3cx problem.

    At minimum you will need another adsl-modem AND router for the new connection. The new router will need a different network "gateway address" to your existing router. eg. just say existing router is 192.168.1.1 . Then make the new router 192.168.1.2 . Then traffic bound for gateway 192.168.1.2 will go out via the new adsl connection. Whereas existing traffic bound for 192.168.1.1 will continue to use the old adsl connection.

    If you are confident dabbling in such things its not hard. But if you don't have basic network understanding then it could be challenging. The sorts of things you will need to configure include :
    • - ensuring only one of the Routers provides the DHCP service to the network and the other DHCP is turned off
      - reduce the range for of the dynamic address pool so that 192.168.1.2 is reserved (for the new router) and not dynamically allocated as it most likely will be now
      - manually configure the "default gateway" on every device you want to use the new adsl connection. This includes the machine that runs 3cx AND every hardware IP phone.

    This is the simplest and easiest way. There are more involved ways that allow for failover and traffic-sharing between the two internet links. But probably best not to go there unless you need to !

    Hope that helps.

    Regards
    thenua
     
  5. htcomm

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    Thanks or the replies.

    Hi Leejor, we have looked at multi- wan routers but have been warned off them for use with VoIP. That maybe somewhat unfair, but I don't know anyone using them for voice applications.

    Hi Thenua. What I want to acheive is to have incoming calls on one adsl circuit to the 3cx and outgoing call through the second adsl circuit.
    We have two sip accounts (one we intend to use for incoming calls and the other one for outgoing), but the difficulty is registering these accounts to different adsl circuits. Maybe I can do it through the routing table, but ideally I wanted 3cx to allow me to select the network interface for each adsl circuit.

    Thanks Htcomm
     
  6. thenua

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    Hi Htcomm,

    No I can't think of any way that 3cx or the network would do it. The answer imo would be pretty extreme. i.e. have 2 separate machines. Each running separate versions of 3cx. One using the first adsl gateway and one using the other adsl gateway.

    Then the challenge is how to bring the two 3cx's together. Perhaps hookup hardware IP phones with two or more accounts and have one account pointing to each of the 3cx instances. The outgoing calls could be programmed through one account to go via 3cx no. 1 which in turn goes via adsl gateway no.1. Whilst incoming calls pass via adsl gateway #2 to 3cx #2 and on to the handset's no.2 account.

    But I am unsure what is driving your need. If one adsl circuit has better bandwidth than the other, wouldn't you just want to use the better one for all SIP traffic ? Its certainly shaping up as a very complicated exercise and not one that I have seen other people try and do.

    Regards
    thenua
     
  7. zanthexter

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    Here's a cheap, simple, and easy solution which uses routers that can act as SIP proxies:

    Assume THREE DSL lines - Line 1 Internet, Line 2 Incoming calls, Line 3 Outgoing calls (if the Internet is on its own line, QoS is less of an issue)
    Assume internal network uses 192.168.1.x addressing.

    Existing Router
    Two D-Link DIR 330 Wireless G VPN routers - $250 total cost - Fast CPU, lotsa RAM.
    Open Source DD-WRT firmware - VOIP or Mega options - be sure to check the "Peacock thread" in the forums for reccomended builds.

    Flash and D-Links with the DDWRT firmware.
    Existing Router is unchanged - LAN IP of 192.168.1.1, DHCP enabled, DHCP default gateway of 192.168.1.1, other settings per your requirements
    Router 2 with 192.168.1.2, DHCP DISABLED, Milkfish SIP proxy ENABLED (but no configuration beyond that), disable WiFi
    Router 3 with 192.168.1.3, DHCP DISABLED, Milkfish SIP proxy ENABLED (but no configuration beyond that), disable WiFi
    Attach each router to a DSL line, configure with public IP info.
    Networked devices, including 3CX, are configured normally, with 192.168.1.1 as default gateway for internet traffic.
    In 3CX configure two SIP Trunks for each provider. Trunk1 with 192.168.1.2 as the SIP proxy, Trunk2 with 192.168.1.3 as the SIP proxy.
    Use 3CX's rules to pick Trunk1 or Trunk2 for outgoing calls. (So you can reroute quickly in a pinch)
    Use your VOIP provider to pick the SIP credentials (of a pair) or Static IP (of a pair) to route incoming calls to
    OR
    Assign the incoming SIP credentials (account? different VOIP providers?) to one trunk, and outgoing ones to the other
    OR
    Under the Advanced tab in provider setup set one trunk to register for INCOMING calls, the other for OUTGOING. (Works with 1 set of credentials)


    This has the effect of:

    1) Regular internet traffice is isolated and cant interfere with calls (and vice versa)
    2) 3CX web portal routed via regular internet connection
    3) You can pick which of the phone DSL lines to accept and make calls on
    4) It's a very "simple" set up, requiring only average networking skills. All the "routing" is done with wires, not complex firewall rules.
    5) It's CHEAP! At $75-150 a pop for the D-Link boxes you aren't breaking the bank.
    6) It's scalable! Just add more DSL lines and more Proxies!

    Caveats -

    There is no load balancing or autofailver. This is just manually routing things using wires and boxes instead of rules.

    I haven't tested this. It SHOULD work. I am also new to 3CX, but fairly capable with networks.

    I don't know how well the DDWRT/Milkfish proxy will handle remote extensions. If you can't just set each remote extension with DSL-A as the prinary SIP server and DSL-B as the secondary (reversed for half the remote extensions) and have it go, you might have to share DSL Line 1 between internet and remote phones or add a DSL line 4.

    DSL should be able to handle 5-15 calls per line, depending on speed, and without other usage. It's all dependant on your upstream, as downstream is usually much higher.

    You could certainly do the same thing with a good multi-WAN capable firewall, but it'd be a lot more complex, but possibly more secure (as one would expect a fancy firewall to have ALLLL the security bells and whistles.)
     
  8. zanthexter

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    The phones and the 3CX should be on the same subnet. If they are not, things are more complex and a pro likely is needed.

    The phone gateways shouldn't matter, as the gateway is only used for non-local (different subnet) things, like the internet. They likely can be left blank or set to the default gateway automatically using DHCP.

    The 3CX will handle all communications using it's gateway. If you set it to DSL 1, and a call comes in on DSL2, the reply will go out via DSL1 with a different source IP and problems ensue. (as in, it wont work)

    Either the 3CX needs to communicate via a smart firewall/router (gateway) with different incoming/outgoing servers, allowing the firewall/router to match each server to a specific DSL line, or it needs to use proxies to get around the gateway issue.
     
  9. thenua

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    Yep - Nice one zanthexter. ;-)
     
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