Harald Alvestrand
Endpoint addresses consist of an AS number, an interface ID, and a “next protocol” address. This last is presumably only useful at SCION endpoints.
My answer:
One of the fields in a SCION address is the ISD (Isolation Domain) number, not the interface ID. We mention "a complete SCION address is composed of the <ISD, AS, endpoint address>” in section 1.3.1. The we show the address header in 2.2.2. If this is too late in the draft, we could add some text earlier to clarify this. Interface IDs, instead, are part of hop fields (interface IDs are in the the ConsIngress / ConsEgress). Perhaps the confusing fact is that the field is called ConsIngress/Egress. This is because these fields refer to interface IDs in the direction the link was discovered during path construction (beaconing).
Harald Alvestrand
There’s a weakly described feature (which still gets 16 bits in the header!) called “ConsIngress” and “ConsEgress”, which says that “routers will do L4 processing”, without calling out what that is - Traceroute is briefly mentioned, but not to a degree that would allow implementation of whatever-it-is-supposed-to-be.
Response:
You are probably referring to the ConsEgress Router Alert flag, right? Thank you for spotting this, the description should be extended. This is actually one bit, we’ll add some explanation on this flag. (I see how the current description is somehow confusing). Besides that, ConsIngress and ConsEgress are just instances of interfaces Identifiers, we probably have to make this clearer.
Regarding traceroute, this is an example of how this might be used (there is a SCON trace route application). As we don’t describe it, I’d remove it.
nicorusti
commented
1 month ago
Current text is confusing
TODOs:
..
Reviewer feedback