Good point regarding non-congruence not necessarily meaning non-separation, and touché on margins (by which I presume you mean SS7 has massive overprovisionining for average traffic). However, the fact remains, it has proven itself to work for a lot longer, and a for much larger subscriber base, with far fewer systemic failures (especially on a per subscriber/expected availability basis), than the current Internet. I notice you didn't answer my request for the peer reviewed literature to support your assertion. To support mine I give (there are hundreds in the literature): Gopel (Nokia): HSN and Multimedia Apps, 5th Conf, IEEE, 2002: Print ISBN: 0-7803-7600-5 PP 161-166 Ramjee et al (Lucent Bell Labs): Comsware 2006: Print ISBN: 0-7803-9575-1 PP 1-10 Khalios et al (City College of NY): IEEE Globecom 2003: Print ISBN: 0-7803-7974-8 PP 3984-3989 Never mind all of Shannon's work and everything bell labs did in developing digital switching. You can always have control traffic follow the same path in a different channel, so you get the same effect of physical interruption, and therefore the topography alerting of an interrupted link, without the issues of pathological traffic in the bearer channel interrupting your control traffic (as with ISDN subscriber trunks).
-----Original Message----- From: Randy Bush [mailto:randy@psg.com] Sent: Tuesday, February 16, 2010 7:56 PM To: Tomas L. Byrnes Cc: Nick Hilliard; NANOG list Subject: Re: BIRD vs Quagga
As in SS7, which has successfully managed the phone system for decades, where the control and data plane are explicitly separated?
and has such wonderful margins
and, btw, separation is not necessarily non-congruence