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Diffstat (limited to 'content/en/blog/20211229-flow-vs-connection.md')
| -rw-r--r-- | content/en/blog/20211229-flow-vs-connection.md | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/content/en/blog/20211229-flow-vs-connection.md b/content/en/blog/20211229-flow-vs-connection.md index 88b3654..3806dd2 100644 --- a/content/en/blog/20211229-flow-vs-connection.md +++ b/content/en/blog/20211229-flow-vs-connection.md @@ -230,6 +230,10 @@ applications' half of the flow deallocation, but not the complete deallocation. If an IPCP crashes, applications still hold the FRCP state and can recover the connection over a different flow[^6]. +**Edit: the below section is not correct, but it's interesting to read +anyway**[^7]. There is a new post, documenting the +[actual implementation](/blog/2022/02/28/application-level-flow-liveness-monitoring/). + So, now it should be clear that the liveness of a flow has to be detected in the flow allocator of the IPCPs, not in the application (again, reminder: FRCP state is maintained inside the application). @@ -264,7 +268,7 @@ in a way similar to the OSI/TCP models. I omitted the "physical layer", which is handled by dedicated IPCP implementations, such as the ipcpd-local, ipcpd-eth, etc. It's not that important here. What is important is that O7s splits functionality that is in TCP/IP in two -layers (L3/L4), into **3 independent layers**[^7] (and protocols). Let's +layers (L3/L4), into **3 independent layers**[^8] (and protocols). Let's go through O7s from bottom to top. {{<figure width="80%" src="/blog/20211229-oecho-5.png">}} @@ -332,7 +336,16 @@ Dimitri [^6]: This has not been implemented yet, and should make for a nice demo. -[^7]: The "recursive layer boundary" in the figure uses the word layer +[^7]: After implementing the solution below, it became apparent to me + that something was off. I needed to leak the FRCP timeout into + the IPCP, which is a layer violation. I noted this fact in my + commit message, but after more thought, I decided to retract my + patch... it just couldn't be right. This layer violation didn't + come up when we implemented FLM in the Flow allocator RINA, + because RINA puts the whole retransmission logic (called DTCP) + in the IPCP. + +[^8]: The "recursive layer boundary" in the figure uses the word layer in the sense of a RINA DIF. We didn't adopt the terminology DIF, since it has special meaning in RINA, and O7s' recursive layers are not interchangeable or compatible with RINA DIFs.
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