CobraNet must operate on a full-duplex network. Repeater hubs in the network are forbidden. Collisions cannot be tolerated.
The connection to a CobraNet device is 100 BASETX copper.
The switch to which it is connected can communicate with other switches by any standard full duplex Ethernet medium, including copper, fiber, 100 Mbit, gigabit and 10 gigabit.
CobraNet can be successfully bridged over other transport mediums, such as SONET. As long as the end links are IEEE 802.3 compliant and timing constraints are observed, it will work. Timing constraints are covered in the section Timing.
CobraNet will work with dedicated full-duplex wireless links, such as Tsunami.
Wi-fi, Powerline and Homeplug are alternative Ethernet technologies that operate in half-duplex mode. CobraNet will not work properly with these technologies. However, a PC connected to the CobraNet network through one of these types of links can properly manage the CobraNet devices using SNMP.
The connection to a CobraNet device must be able to auto-negotiate the connection type.
If you are using an optical to copper media converter in the link attached to a CobraNet device, make sure it can bridge auto-negotiation. Not all will do this, although absence of this feature is becoming less common.
Notes:
Low bandwidth, half-duplex links such as these can be overloaded by the large amount of traffic that can exist on a CobraNet network. These links will support SNMP, but may still not work well due to the bandwidth they are exposed to.
Although CobraNet requires a 100 BASETX full duplex link, never explicitly set switch ports to operate in this mode. This will disable auto-negotiation on the port and the attached CobraNet device will not work.
