Howdy.
I have been selected as the Applications Area Review Team reviewer for this
draft (for background on apps-review, please see
http://www.apps.ietf.org/content/applications-area-review-team).
Please resolve these comments along with any other Last Call comments you may
receive. Please wait for direction from your document shepherd or AD before
posting a new version of the draft.
Document: draft-ietf-grow-geomrt-01
Title: MRT BGP routing information export format with
geo-location extensions
Reviewer: D. Crocker <[email protected]>
Review Date: 27 April 2011
Summary:
This document provides a focused enhancement to an existing data
specification for exchanges reports about BGP activity externally. It adds
geo-location information to the tables.
Major Issues:
0) The specification generally appears reasonable and concise. The
enhancement seems intuitively useful, although I strongly suggest the document
make the types of utility explicit. Why is it good to add this information to
the table?
1) The document presumes extensive background by the reader. Instead it
needs a bit of tutorial and it needs to define every term -- acronym or core
vocabulary -- it uses, either directly or by citation
2) The GEO_PEER_TABLE needs a column with text defining the meaning of each
value, rather than relying on the labels' being intuitive.
Detailed comment:
MRT BGP routing information export format with geo-location extensions
draft-ietf-grow-geomrt-01.txt
Abstract
This document extends the Border Gateway Protocol (BGP) MRT export
format for routing information to include terrestrial coordinates.
Expand MRT so that the Abstract requires less background to understand and gives
a basic sense of the purpose/benefit of this work.
2. Introduction
Research is underway that analyzes the network behavior of routing
protocol transactions from routing information base snapshots in
relation to geographical coordinates. Specifically the BGP routing
The first sentence is confusing. Although I could make guess, I don't really
know what it means. I suggest less redundant vocabulary and possibly two
sentences and probably more active sentence form.
In contrast, I find draft-ietf-grow-mrt's related sentence:
"Researchers and engineers often wish to analyze network behavior by
studying routing protocol transactions and routing information base
snapshots."
to be reasonably clear.
protocol is the subject of study and the analysis has been
significantly aided by the availability and extension of the "MRT
format" [I-D.ietf-grow-mrt] originally defined in the MRT
Programmer's Guide [MRT PROG GUIDE].
This memo documents an extension to the "MRT format"
[I-D.ietf-grow-mrt] and introduces an additional definition of a MRT
Subtype field.
Lots of acronym repetition, without any acronym definition.
3. Geo-location aware MRT Routing Information Subtype
The additional Subtype is defined for the TABLE_DUMP_v format, which
extends the TABLE_DUMP_V2 type.
3.1. GEO_PEER_TABLE
The GEO_PEER_TABLE Subtype updates the TABLE_DUMP_v2 Types to include
Geo-location information in the form of WGS84 [WGS 84] formatted
coordinates. The MRT subtypes would be as follows.
1 PEER_INDEX_TABLE
2 RIB_IPV4_UNICAST
3 RIB_IPV4_MULTICAST
4 RIB_IPV6_UNICAST
5 RIB_IPV6_MULTICAST
6 RIB_GENERIC
7 GEO_PEER_TABLE
What does each of these value mean?
The labels might seem intuitive, but there should be explicit text defining
their meaning.
The GEO_PEER_TABLE MRT record provides the BGP ID of the collector,
Its latitude and longitude in WGS84 [WGS 84] format, and a list of
indexed peers.
I'm guessing this is the single most important text in the document, since it
specifies exactly what location info is being provided. I suggest the Abstract
and Introduction summarize this, along the lines of:
...to include terrestrial coordinates of the BGP collector.
On the other hand, I can't find a definition of what a BGP Collector is, in this
or related documents. (It's not in RFC 4271, for example.) In looking over the
vocabulary from RFC 4271, it does appear that there is no term for the system
that receives BGP reports. Clearly one is needed, but it needs to be defined
explicitly, so please either provide definition text or cite it.0
In fact, it's probably a good idea to explain why this particular bit of
information is useful. A small segment of tutorial text would go a long way.
Depending on what the definition of a BGP Collector is, the usefulness might or
might note be obvious, but it shouldn't be left to chance.
The format and function of the Collector BGP ID, Peer Count are as
defined by the TABLE_DUMP_V2 MRT PEER_INDEX_TABLE format.
[I-D.ietf-grow-mrt].
The Collector Latitude and Collector Longitude are the geographical
coordinates of the collector in WGS84 [WGS 84] datum decimal degrees
format stored as a single precision float in the 32 bits allocated to
the Collector Latitude and Collector Longitude. The latitude and
longitude may be a Not A Number (NAN) for situations where the geo-
It's not required, but common practice is to capitalize normative terms, like
MAY.
location of the collector is considered private. The Collector
Latitude and Collector Longitude MUST NOT be a mix of WGS84 [WGS 84]
datum coordinate and NAN values.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Collector BGP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Collector Latitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Collector Longitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Count | Peer entries (variable)
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format of the peer entries is shown below. The Peer Type and the
Peer BGP ID is as defined in the TABLE_DUMP_V2 MRT
[I-D.ietf-grow-mrt] PEER_INDEX_TABLE format. The order of the Peer
entries in GEO_PEER_TABLE MUST match the order and number as existing
in the PEER_INDEX_TABLE.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer BGP ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Latitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Longitude |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Peer Latitude and Peer Longitude are the geographical coordinates
of the peer in WGS84 [WGS 84] datum decimal degrees format stored as
a single precision float in the 32 bits allocated to the Peer
Latitude and Peer Longitude. The latitude and longitude may be a Not
MAY
--
Dave Crocker
Brandenburg InternetWorking
bbiw.net
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