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  1. #1
    Join Date
    Feb 2007
    Posts
    240

    Bacnet/ip over internet

    Is there any way to run bacnet over Internet, I hear that nat addressing breaks it down

  2. #2
    Join Date
    Feb 2005
    Posts
    1,226
    look up BBMD functionality in BACnet.
    Most high level bacnet controllers have this feature but it needs to be enabled. Each internet segment/subnet of your network requires one device to act as the BBMD.
    The BBMDs talk to each other by encapsulating BACnet packets in standard TCP format, that is why they can cross internet routers. Once the other BBMD gets the packet it unbundles it to a standard BACnet packet and passes it to the BACnet device that resides on its segment.

  3. #3
    Join Date
    Nov 2006
    Location
    New Hampshire
    Posts
    255
    As long as the BBMDs have external IP addresses that can be seen from the internet it's not a problem. The current Bacnet/IP standard does not address NAT so if your devices sit on an internal IP with a router doing port forwarding from a common external IP then the messages will get lost.

  4. #4
    Join Date
    Jun 2007
    Location
    Cleveland, Ohio
    Posts
    184
    Agreed with both previous posts. We have tried this and it will not work behind a firewall. You need to have a BBMD on both sides with a real world WAN IP address. You can get away with inter-corporate WAN bridging if you have a VPN but you need higher level Cisco Routers to take care of this. The issue is just when you start crossing subnets things get lost in the shuffle.

  5. #5
    Join Date
    Sep 2007
    Location
    Under the sea
    Posts
    233
    On a firewall you have to allow UDP/IP on port 47808.

    Most IT people freak out on opening ports.
    But after the they check into the BACnet protocol and the reserved BAC0 (47808) port they slowly begin to come around.

    It's totally safe.

  6. #6
    Join Date
    Jun 2007
    Location
    Cleveland, Ohio
    Posts
    184
    This is a long document but check it out and it does a good job at explining the quirks... http://www.bacnet.org/Bibliography/ES-7-99/IPPART1.HTM

  7. #7
    Join Date
    Feb 2007
    Posts
    240
    Quote Originally Posted by AutoPilot View Post
    On a firewall you have to allow UDP/IP on port 47808.

    Most IT people freak out on opening ports.
    But after the they check into the BACnet protocol and the reserved BAC0 (47808) port they slowly begin to come around.

    It's totally safe.
    I think theirs more to it that just opening up 47808, I have done this and I can connect to the device, however whenever I tried to view any points the link breaks down.
    I do have a BBMD, however they are behind firewalls.
    So basically my question is what do 2 BBMD's need to see each other, just 47808?

    Thanks for the info, Im sifting through it now

  8. #8
    Join Date
    Feb 2007
    Posts
    240
    Quote Originally Posted by Webbyz View Post
    This is a long document but check it out and it does a good job at explining the quirks... http://www.bacnet.org/Bibliography/ES-7-99/IPPART1.HTM
    That is a good document!, Thanks Webby

    If refers to a sourcforge application http://sourceforge.net/projects/bfr
    Has anyone here used it?

  9. #9
    Join Date
    Sep 2007
    Location
    Under the sea
    Posts
    233
    What software are you using?

    I run several remote sites with Andover, Delta, and Tridium.
    I've never had any problems with BBMD.

    I take that back... Sometimes a JACE can be fussy about the network connections.

  10. #10
    Join Date
    Feb 2007
    Posts
    240
    Summit

  11. #11
    Join Date
    Aug 2005
    Location
    Oahu, Hawaii
    Posts
    107
    I think theirs more to it that just opening up 47808, I have done this and I can connect to the device, however whenever I tried to view any points the link breaks down.
    I do have a BBMD, however they are behind firewalls.
    So basically my question is what do 2 BBMD's need to see each other, just 47808?
    Try this as a workaround:
    Router #1
    Internal IP 192.168.1.10
    External IP 45.125.100.101
    Router #2
    Internal IP 192.168.5.15
    External IP 67.101.45.100

    In your BBMD tables, use the External addresses. So router #1 will have the IP address of 67.101.45.100 to find router #2. Router #2 will have the IP address of 45.125.100.101 to find router #1.
    Set Router #1's NAT firewall's to port forward traffic on 47808 to the internal Bacnet router's address of 192.168.1.10.
    Set Router #2's NAT firewall's to port forward traffic on 47808 to the internal Bacnet router's address of 192.168.5.15.
    This should get your Bacnet traffic to work.

  12. #12
    Join Date
    Aug 2006
    Posts
    61

    Thanks

    Thanks for the info guys. These posts will help some of the guys at my office.
    "I wish it were winter so we could freeze it into ice blocks and skate on it and melt it in the spring time and drink it!"

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