Re: [Openslp-devel] Problem with losing SA registration in the presence of DA

[Nou D. <nd...@te...>]

Haven't seen any responses but I've narrowed it down with some
experimentation and ethereal traces so I have a more specific question.
The behaviour is as described before; when the devices come up they do a
Service Request for a directory-agent and find it but according to
RFC2608, p.39:
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12.1. Directory Agent Rules
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   When DAs are present, each SA MUST register its services with DAs
   that support one or more of its scope(s).
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This is definitely not happening, after the Service Request there is a
DA Advertisement from the DA, then the UA/SA initiates a TCP connection
to the DA and does a service request and gets an empty response.  (All
scopes are "default" by the way.)  My understanding is that the SA
should do some kind of service advertisement for the services that the
SA knows about (is that right?).
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So my specific question is: Where in the OpenSLP code does the SA
register its services with a discovered DA?  (The routine name would
suffice I'm sure.)
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Thanks again.... N
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---
Nou Dadoun
nd...@te...
604-628-1215
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________________________________

From: Nou Dadoun=20
Sent: Tuesday, June 20, 2006 10:33 AM
To: 'ope...@li...'
Subject: Problem with losing SA registration in the presence of DA


Hi folks,
I've successfully ported OpenSLP to our embedded device (embedded OS and
commercial TCP/IP stack) and everything's working fairly nicely but I've
run into a problem that I've tried to trace but can't see the cause of.
Each device has an SA (slpd daemon) and also acts as a UA to discover
other like devices and everything works great with multicast etc.  I'm
trying to ensure that the deployment can work even in situations where
multicast won't, e.g. where the devices are on different subnets.  My
thought was that if I install a DA in some routable location (e.g. one
of the subnets or even a third subnet) and let the devices know where
the DA is through DHCP provisioning with the SLP tags, that further
registration and discovery can be done via unicast to/from the DA
avoiding the potentially problematic use of multicast.  (I assume that
this must be a standard approach for this problem.)
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So far so good but as soon as I add a local DA (i.e. windows slpd
configured with .isDA), the individual devices seem to lose (or ignore)
their registration (oddly they still respond to service:service-agent
but not their individual device registration); I've traced the device
registration and it still seems to work and adds the entry to the SA
database but the UA doesn't report it.  Anybody seen this problem
before? (I saw a similar query in the archives but there was no
followup.) Anybody else tried this approach before?  Did it work?  Did
you have to do anything heroic to make it work?  =20
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Thanks ... N
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PS I should mention that my port is of 1.2.0 to ensure that it would
work on our windows testbed; everything I read indicated that 1.2.1 was
broken for XP .. N
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---
Nou Dadoun
nd...@te...
604-628-1215
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