[157859] in North American Network Operators' Group
RE: Whats so difficult about ISSU
daemon@ATHENA.MIT.EDU (Frank Bulk)
Mon Nov 12 17:24:34 2012
From: "Frank Bulk" <frnkblk@iname.com>
To: "'Kasper Adel'" <karim.adel@gmail.com>
In-Reply-To: <CALb2afMRykjAP5SXD_R-dr_Cj4UMmy3E=FUuOe_M8HPGJ_Mm4g@mail.gmail.com>
Date: Mon, 12 Nov 2012 16:24:09 -0600
Cc: NANOG list <nanog@nanog.org>
Reply-To: frnkblk@iname.com
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Compared to our CMTS, our class 5 softswitch cost us less money. Yet our
CMTS vendor stopped talking about hitless software upgrades 2 years ago
because the upgrade path (from, to, and which software releases you can use)
is so limited it's hardly practical.
Frank
From: Kasper Adel [mailto:karim.adel@gmail.com]
Sent: Monday, November 12, 2012 12:22 AM
To: Frank Bulk
Cc: NANOG list
Subject: Re: Whats so difficult about ISSU
Hi Frank,
Is it because C5 softswitches have expensive hardware, advanced software and
dual asics? I would have never imagined that any vendor is capable of
upgrading fpd's/ASICs ucode without a hit unless there are multiple chips
continuously syncing with each other.
Regards,
Kim
On Monday, November 12, 2012, Frank Bulk wrote:
We do it on our Class 5 softswitch ... and it works consistently. There may
be a few seconds, once, where a new call can't be made, but most people will
re-dial. It just works.
It can be done, but the product has to be built with that in mind.
Frank
-----Original Message-----
From: Kasper Adel [mailto:karim.adel@gmail.com <javascript:;> ]
Sent: Thursday, November 08, 2012 5:23 PM
To: NANOG list
Subject: Whats so difficult about ISSU
Hello,
We've been hearing about ISSU for so many years and i didnt hear that any
vendor was able to achieve it yet.
What is the technical reason behind that?
If i understand correctly, the way it will be done would be simply to have
extra ASICs/HW to be able to build dual circuits accessing the same memory,
and gracefully switch from one to another. Is that right?
Thanks,
Kim
