3 ms·

Sounds like source routing. It’s an idea that was abandoned early on, but I’d be interested in learning if things are different. Sometimes old abandoned ideas c

by api 5y ago

Sounds like source routing. It’s an idea that was abandoned early on, but I’d be interested in learning if things are different. Sometimes old abandoned ideas can be revisited due to new approaches, algorithmic or design innovation, or Moore’s law.

philprx 5y ago
Yeah sounds a bit like it, at least scion would be a superset as it embeds many other concepts. IMHO, source routing concept is not abandoned as Segment Routing seems to be used in specialized / large networks: https://en.wikipedia.org/wiki/Segment_routing https://en.wikipedia.org/wiki/Segment_routing
caust1c 5y ago
I believe it's a bit of this and a bit of that. My understanding is that source routing wasn't widely adopted because it couldn't quickly adapt to changes and partitions. Now that we can calculate routes trivially on consumer grade hardware, perhaps that's a forcing function? Come to think of it, I see this as a conceptual extension and optimization on BGP Policy Based routing. Seems like it's removing the overhead and formally separating the control protocols from the data protocols.
kilburn 5y ago
This is explicitly answered in the second blog post [2] of a 3-part [1,2,3] series over at the anapaya website: > A careful reader may have gotten the impression that SCION is simply source routing in disguise, however, this is not the case for a variety of reasons. First of all, end hosts do not learn any information about topology inside the Autonomous System (AS) - this is still under the control of the local network administrators who may want to implement complicated firewall rules or in any other way affect the traffic in their local networks. > While with SCION the end-host selects the path of the packet, it cannot perform this selection completely independently. Instead, the network operator distributes the available paths and the end-host can only choose from this pre-selected set. [1] https://www.anapaya.net/blog/the-scion-series-part-1 https://www.anapaya.net/blog/the-scion-series-part-1 [2] https://www.anapaya.net/blog/the-scion-series-part-2 https://www.anapaya.net/blog/the-scion-series-part-2 [3] https://www.anapaya.net/blog/the-scion-series-part-3 https://www.anapaya.net/blog/the-scion-series-part-3

by api 5y ago

philprx 5y ago

Yeah sounds a bit like it, at least scion would be a superset as it embeds many other concepts. IMHO, source routing concept is not abandoned as Segment Routing seems to be used in specialized / large networks: https://en.wikipedia.org/wiki/Segment_routing https://en.wikipedia.org/wiki/Segment_routing

caust1c 5y ago

I believe it's a bit of this and a bit of that. My understanding is that source routing wasn't widely adopted because it couldn't quickly adapt to changes and partitions. Now that we can calculate routes trivially on consumer grade hardware, perhaps that's a forcing function? Come to think of it, I see this as a conceptual extension and optimization on BGP Policy Based routing. Seems like it's removing the overhead and formally separating the control protocols from the data protocols.

kilburn 5y ago

This is explicitly answered in the second blog post [2] of a 3-part [1,2,3] series over at the anapaya website: > A careful reader may have gotten the impression that SCION is simply source routing in disguise, however, this is not the case for a variety of reasons. First of all, end hosts do not learn any information about topology inside the Autonomous System (AS) - this is still under the control of the local network administrators who may want to implement complicated firewall rules or in any other way affect the traffic in their local networks. > While with SCION the end-host selects the path of the packet, it cannot perform this selection completely independently. Instead, the network operator distributes the available paths and the end-host can only choose from this pre-selected set. [1] https://www.anapaya.net/blog/the-scion-series-part-1 https://www.anapaya.net/blog/the-scion-series-part-1 [2] https://www.anapaya.net/blog/the-scion-series-part-2 https://www.anapaya.net/blog/the-scion-series-part-2 [3] https://www.anapaya.net/blog/the-scion-series-part-3 https://www.anapaya.net/blog/the-scion-series-part-3