[Sipdht-devel] CHORD Fingers

[Mosiuoa T. <g06...@ca...>]

Hi all!

I have been testing out the sipdht-0.0.2 release.  Its working fine, but I have a query about the finger table entries that are generated when I simlulate nodes joining the overlay (DHT).  The DHT surely is based on CHORD since it uses finger tables (and draft-bryan-sipping-p2p-02 uses CHORD as example).

Say three nodes (127.0.1.1, 127.0.1.2 and 127.0.1.3) join the overlay (in that order).    And say [2] bootstraps through [1] and [3] through [2].  Using the sipdhtq command for displaying finger tables of the nodes with hash cardinality of 8, I get for [1]:

Finger 0: (0x2) : sip:2@127.0.1.1
Finger 1: (0x3) : sip:2@127.0.1.1
Finger 2: (0x5) : sip:2@127.0.1.1
.......

Finger 0 gives the immediate successor of the node in the circular space, which I understand.  [2] is the immediate successor for [1], ok.  But I don't understand the i^th   entries for the finger tables of [1].  Using the formula s = successor(n + 2^i-1  ) formula, I should get for [1]:

Finger 0: (0x2) : sip:2@127.0.1.1
Finger 1: (0x3) : sip:3@127.0.1.1
Finger 2: (0x5) : sip:1@127.0.1.1
.......

Please help me out if I got my understanding of CHORD mixed up, or I'm failing to interpret the output correctly.

Again, if I use cardinality of 8, I also thought it would only give three lines of output (m=3 for three bit identifiers if there are 8 nodes: 0-7) for each node's finger tables.

Thanks again!