Hi,
I don't think the proxy will work as the devices will not generate the HTTP message. Please have a look and let me know if I am wrong.
It is all because of the Non IP support of the 3GPP NBIOT. All these devices will not have an IP address. These devices will communicate using Data Over NAS. Now, when the CoAP message generated by the device reaches SCEF(Service Capability Exposure Function 3GPP TS 23682), it will post the received CoAP message over HTTP REST to the CoAP server. So, what I am worried here is when SCEF posts the CoAP message to over HTTP, how will it do. The entire CoAP message will be sent as a HTTP payload.
Now, how will the message structure look like?
[3GPP-TS_24.301] defines the transport of user data via
the control plane procedure. Two dedicated NAS messages are specified for
transferring small data via the MME, see CONTROL PLANE SERVICE REQUEST message
and ESM DATA TRANSPORT message in 3GPP [3GPP-TS_24.301]. For initiation of user data
transport via the control plane the CONTROL PLAN SERVICE REQUEST message is
used which may include ESM DATA TRANSPORT message in its IE “ESM message
container”. After the initiation of user data transport via control plane the
separate ESM DATA TRANSPORT messages may be used for further transport of user
data.
CoAP
messages are placed into the IE “User data container” of the ESM DATA TRANSPORT
message.
In
case DTLS is used the same applies to the DTLS messages.