Loading ...
Sorry, an error occurred while loading the content.

UDP port issues in the Network Port object

Expand Messages
  • nomeekgeek
    Currently, the Network Port object does not have a separate property to specify the UDP port for BACnet/IP. Instead, the port is assumed to be specified as
    Message 1 of 1 , Jun 4, 2012
    • 0 Attachment
      Currently, the Network Port object does not have a separate property to specify the UDP port for BACnet/IP.  Instead, the port is assumed to be specified as part of various B/IP addresses. 

      But there seem to be a number of ambiguities and possible problems with this approach.  This message examines each property that contains an IP address or hostname with respect to the UDP port to be used.
      • MAC_Address.  This must be the address used in BACnet network headers.  Thus, it must be the B/IP address including the UDP port.  If the property is writeable, then the port can be set along with the IP address.  BUT: if the port is using DHCP, this property seems likely to be read-only.  In that case, how is the UDP port set?  In San Francisco, a proposal (in a different context) for a property being "write part, ignore the rest" was not greeted favorably.
      • BACnet_IP_Multicast_Address (OCTET_STRING).  Since this replaces a link-local broadcast, it should presumably uses the same UDP port as MAC_Address.  But does this property INCLUDE the UDP port - which would allow an attempted write to specify a different port than MAC_Address - or is it just the IP address portion?
      • BBMD_Global_IP_Address is a BACnetHostAddress.  12.X.27 says this is "public IP address and UDP port".  But the comment on the ip-address choice in BACnetHostAddress says "4 bytes".  We COULD change the comment to 6 bytes, but that would conflict with usage of BACnetHostAddress by BACnetHostNPort, which adds port explicitly.
      If the hostname CHOICE is used, would we append the port as ":47808"?
      We COULD change the property to BACnetHostNPort instead of BACnetHostAddress, although the "hostname" CHOICE might be questionable.
      • BBMD_Broadcast_Distribution_Table is a list of BACnetBDTEntry.  This explicitly has a UDP port for each entry and so is OK.
      • BBMD_Foreigh_Device_Table is a list of BACnetFDTEntry.  Comment says "6 octet B/IP address", which includes the UDP port and so is OK.
      • FD_BBMD_IP_Address is a BACnetHostNPort.  Explicitly has a UDP port and so is OK
      • BACnet_IP_Subnet_Mask, BACnet_IP_Default_Gateway, BACnet_IP_DNS_Server, BACnet_IP_DHCP_Server are all IP address only, and so are OK.

    Your message has been successfully submitted and would be delivered to recipients shortly.