Prop. 159 relay notes

i2p2www/spec/proposals/159-ssu2.rst

@@ -5,7 +5,7 @@ SSU2
     :author: eyedeekay, orignal, zlatinb, zzz
     :created: 2021-09-12
     :thread: http://zzz.i2p/topics/2612
-    :lastupdated: 2022-07-09
+    :lastupdated: 2022-07-10
     :status: Open
     :target: 0.9.56
 
@@ -6099,6 +6099,10 @@ or Bob's address, sent to Bob by Alice.
 Relay Tag Request
 ```````````````````````
 This may be sent by Alice in a Session Request, Session Confirmed, or Data message.
+Not supported in the Session Created message, as Bob doesn't have Alice's RI yet,
+and doesn't know if Alice supports relay.
+Also, if Bob is getting an incoming connection, he probably doesn't need introducers
+(except perhaps for the other type ipv4/ipv6).
 
 When sent in the Session Request,
 Bob may respond with a Relay Tag in the Session Created message,
@@ -7372,6 +7376,19 @@ there are several options to validate the signature:
 - Don't validate the signature at all
 
 
+Tag Requests by Bob
+------------------------
+In SSU 1, only Alice could request a tag, in the Session Request.
+Bob could never request a tag, and Alice could not relay for Bob.
+
+In SSU2, Alice generally requests a tag in the Session Request,
+but either Alice or Bob may also request a tag in the data phase.
+Bob generally is not firewalled after receiving an inbound request,
+but it could be after a relay, or Bob's state may change,
+or he may request an introducer for the other address type (IPv4/v6).
+So, in SSU2, it is possible for both Alice and Bob to simultaneously be relays for the other party.
+
+
 
 Published Router Info
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