nanog mailing list archives
Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?)
From: Masataka Ohta <mohta () necom830 hpcl titech ac jp>
Date: Mon, 22 Jun 2020 21:49:24 +0900
Robert Raszuk wrote:
Neither link wise nor host wise information is required to accomplish say L3VPN services. Imagine you have three sites which would like to interconnect each with 1000s of users.
For a single customer of an ISP with 1000s of end users. OK. But, it should be noted that a single class B routing table entry often serves for an organization with 10000s of users, which is at least our case here at titech.ac.jp. It should also be noted that, my concern is scalability in ISP side.
Moreover if you have 1000 PEs and those three sites are attached only to 6 of them - only those 6 PEs will need to learn those routes (Hint: RTC - RFC4684)
If you have 1000 PEs, you should be serving for somewhere around 1000 customers. And, if I understand BGP-MP correctly, all the routing information of all the customers is flooded by BGP-MP in the ISP. Then, it should be a lot better to let customer edges encapsulate L2 or L3 over IP, with which, routing information within customers is exchanged by customer provided VPN without requiring extra overhead of maintaining customer local routing information by the ISP. If a customer want customer-specific SLA, it can be described as SLA between customer edge routers, for which, intra-ISP MPLS may or may not be used. For the ISP, it can be as profitable as PE-based VRF solutions, because customers so relying on ISPs will let the ISP provide and maintain customer edges. The only difference should be on profitability for router makers, which want to make routing system as complex as possible or even a lot more than that to make backbone routers a lot profitable product.
With nested labels, you don't need so much labels at certain nesting level, which was the point of Yakov, which does not mean you don't need so much information to create entire nested labels at or near the sources.
Label stack is here from day one.
Label stack was there, because of, now recognized to be wrong, statement of Yakov on day one and I can see no reason still to keep it. Masataka Ohta
Current thread:
- Re: Devil's Advocate - Segment Routing, Why?, (continued)
- Re: Devil's Advocate - Segment Routing, Why? Randy Bush (Jun 19)
- Re: Devil's Advocate - Segment Routing, Why? Dorian Kim (Jun 19)
- why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Randy Bush (Jun 19)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 20)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Robert Raszuk (Jun 20)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Mark Tinka (Jun 21)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 21)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Mark Tinka (Jun 21)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 21)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Robert Raszuk (Jun 21)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 22)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Mark Tinka (Jun 22)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 23)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Owen DeLong (Jun 23)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 24)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Nick Hilliard (Jun 22)
- RE: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) adamv0025 (Jun 22)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Mark Tinka (Jun 22)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Masataka Ohta (Jun 23)
- BGP flooding Robert Raszuk (Jun 23)
- Re: why am i in this handbasket? (was Devil's Advocate - Segment Routing, Why?) Mark Tinka (Jun 21)