CODEWITHSUNDEEP
network-programmingterminologynetwork-protocols
jacobq
jacobq

Reputation: 11577

What is the proper terminology (Application Layer, Transport layer, etc.) when "wrapping" one protocol inside another?

I am designing an application that communicates with devices over various connection types / transport mechanisms. For example, USB Virtual COM, serial port, and TCP connections. In each case I will be using a custom/device-specific application protocol (e.g. to send commands, receive data, etc.) passed through the underlying transport. For the cases mentioned so far it seems pretty clear to me that the "Application Protocol" is the proprietary command/response one and TCP connection (or serial port or "whatever magically transports the bytes") is the Transport Protocol.

However, what is the best way to talk about intermediate protocols, for example, when encapsulating the aforementioned proprietary application layer protocol inside of another application layer protocol like SSH, HTTP, or SSL/TLS?

This answer to a different question suggests that:

  1. It's not so important what you call it (with which OSI layer it is associated)
  2. Something like this might be correctly described as an application layer protocol that happens to have another application layer protocol built on top of it.

Bottom line: How should I label this detail in the GUI? Perhaps one of the following?

✔ "Tunnel" or "Tunneling Protocol" (as suggested by @EJP)

Other possibilities included:

Nothing seems to jump out at me as fitting.

Update: As @EJP pointed out, SSL/TLS is an application layer protocol not a transport protocol; the question now reflects this.

Upvotes: 1

Views: 307

Answers (1)

user207421
user207421

Reputation: 310980

However, what is the best way to talk about intermediate protocols, for example, when encapsulating the aforementioned proprietary application layer protocol inside of another application layer protocol like SSH or HTTP or even another transport layer protocol like SSL/TLS?

Every protocol you have mentioned here is an application layer protocol.

You might want to use the word 'tunnelling'.

It's not so important what you call it (with which OSI layer it is associated)

There's no reason to associate it with any of the OSI layers at all. The OSI model is for the OSI protocol suite, which is defunct, ergo so is the model. It's unfortunate that generations of teachers have taught it as though it was a fundamental law of nature. It isn't. If you're using TCP/IP, it has its own layer model, for example, and even the OSI guys admit that nobody ever knew what went into the presentation layer.

Upvotes: 1

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