Device Discovery
Device discovery may not be required for all EEVideo systems. Some systems may preconfigure their cameras, controllers, and networks so they all know how to communicate on power up without any additional configuration.
Other systems may use off-the-shelf EEVideo cameras delivered with a standard configuration from the factory or use devices that set their own dynamic IP addresses using DHCP or ZeroConf protocols. In these cases and many others, a method of searching the network for cameras is helpful.
CoAP Multicast Discovery
EEVideo leverages the Multi-cast Dicovery features alredy specified by the Constrained Application Protocol (CoAP RFC7252) using the Constrained RESTful Environments (CoRE) Link Format (RFC6690) . These protocols work together to build a standard method to find specific devices and services on Ethernet networks.
Request Implementation
Each discovery-capable EEVideo device shall acknowledge request packets with the following parameters.
Discovery IP Destination Address
EEVideo devices supporting Device Discovery shall monitor the standard CoAP IPv4 multicast address: 224.0.1.187.
Discovery Destination Port
EEVideo devices supporting Device Discovery shall open the standard CoAP UDP port: 5683.
Discovery URL
EEVideo devices supporting Device Discovery shall respond to GET requests with the following URI options.
| Field | String | Description |
|---|---|---|
Uri-Path |
".well-known" |
Specifies the well-known locations scheme, RFC5785 |
Uri-Path |
"core" |
Specifies the CoRE Link Format, RFC6690 |
query |
"rt=eev.cam" |
Specifies the EEVideo Camera resource type (a requested CoRE Parameter Resource Type) |
query |
"if=eev.reg" |
Specifies the EEVideo Register based service type (a requested CoRE Parameter Link Target Attribute ) |
Response Implementation
Discovery Response Destination Fields
EEVideo devices supporting Device Discovery shall deliver responses to the MAC address, IP address, and UDP port contained in the source fields of the request packet headers. These fields are included in the header destination fields of the CoAP UDP IPv4 acknowledge packet.