From 66eb64b6136da4b7e1e143e308be8a626d50f080 Mon Sep 17 00:00:00 2001 From: Pavel 'LEdoian' Turinsky Date: Mon, 17 Jul 2023 10:09:37 +0200 Subject: [PATCH] Section about area structure, other chapter headings. --- en/chap02.tex | 29 +++++++++++++++++++++++++++++ en/chap03.tex | 1 + en/chap04.tex | 1 + en/chap05.tex | 1 + en/thesis.tex | 3 +++ 5 files changed, 35 insertions(+) create mode 100644 en/chap03.tex create mode 100644 en/chap04.tex create mode 100644 en/chap05.tex diff --git a/en/chap02.tex b/en/chap02.tex index 4097d0b..387fe59 100644 --- a/en/chap02.tex +++ b/en/chap02.tex @@ -229,3 +229,32 @@ system. \XXX{netsplit, multi links w/ same and diff costs, v2 vs v3, mixed segments, multiple prefixes. napsat na kolejích s gennetem..} + +\section{Area structure} + +It is also worth to consider the expected size and structure of an OSPF areas +where Birdvisu might run. While it is up to the administrator and they may be +very creative, there are some limits to such creativity. + +The largest system which can be spanned by a single OSPF instance is the whole +autonomous system (AS). The largest ASes only have about several hundred +thousand routers\cite{as-topologies}. The average degree also seems to be rather +low. + +We can derive another limit from IPv4 address allocations. A /8 block (i.e. +Class A) has 16 777 216 addresses. Very few ISP would be assigned such a large +block, but they might be using the 10.0.0.0/8 private block. Even if an ISP +wants to use all those addresses, majority of them will likely not be assigned +to routers, but to some end devices that actually provide \uv{useful} services. +Those devices are also likely to be grouped into non-trivial networks, thus +reducing the number of vertices (i.e. routers and networks) in the OSPF +topology. (While IPv6 allocates many more addresses, we assume that the overall +topology will not be different from the IPv4 one.) + +It is probably not practical to have a single OSPF area span all the routers in +a large AS, since any link state change results in an LSA being flooded +throughout the area. + +While we cannot be sure about particular administrative decisions, given the +observations above, we expect that a single area contains at most few thousand +vertices and probably much less than that. diff --git a/en/chap03.tex b/en/chap03.tex new file mode 100644 index 0000000..1d283f8 --- /dev/null +++ b/en/chap03.tex @@ -0,0 +1 @@ +\chapter{Design}\label{ch:design} diff --git a/en/chap04.tex b/en/chap04.tex new file mode 100644 index 0000000..acd42ee --- /dev/null +++ b/en/chap04.tex @@ -0,0 +1 @@ +\chapter{Usage}\label{ch:usage} diff --git a/en/chap05.tex b/en/chap05.tex new file mode 100644 index 0000000..9cfe538 --- /dev/null +++ b/en/chap05.tex @@ -0,0 +1 @@ +\chapter{Evaluation}\label{ch:evaluation} diff --git a/en/thesis.tex b/en/thesis.tex index 4ea2319..e8b8862 100644 --- a/en/thesis.tex +++ b/en/thesis.tex @@ -12,6 +12,9 @@ \include{intro} \include{chap01} \include{chap02} +\include{chap03} +\include{chap04} +\include{chap05} \include{epilog}