Re: [Geopriv] GEOPRIV Experiment at IETF 71

From: Richard Barnes ^lt;>
Date: Fri Apr 04 2008 - 10:08:43 EDT

Hi Karl Heinz,

Glad to provide more details. See responses inline:

> Any problems with the setup? Is NetDisco suitable? What about the SNMP
> traffic caused by your setup? How often did you do the SNMP querries?

This was actually something that we the experimenters (James, Hannes,
and I), didn't have access to. Bill Fenner from the NOC reconfigured
NetDisco to offer an XML/HTTP interface, and we just used that
interface. The way it worked was that the LIS would send a GET to a URL
of the following form ...


... and the result would be an XML structure of the following form ...

   <ROOM>Franklin 6/7</ROOM>

The LIS simple re-packaged that civicAddress structure into a PIDF-LO
document in a HELD locationResponse and returned it to the client.

> Did you collect data in advance or did you do the location
> determination on demand? How many switches/access points did you
> query?

The location we returned was just the location of the AP that the client
IP was connected to. The locations of the APs were entered into the
NetDisco database manually, as they were being installed. I don't know
the precise number, but I think that Bill said they had 100-200 APs.

> How many clients were in your database?

Again, the LIS wasn't maintaining the database, just querying NetDisco
for locations in the manner described above. So the LIS had access to
the positions of all the hosts connected to the IETF network (>1K, I
think?). On the other hand, we only had 5 or 6 users of the experiment
(because the client software I wrote didn't run very well), so the LIS
only ever queried for location on a few hosts.

> How did you detect changes/new clients in the network?

This was a NetDisco internal function, but I think that NetDisco was
querying access points for updates at around a 5 minute interval.

> How long did a location request last?

I don't have precise numbers (that would have been a good idea!), but it
was reasonably fast, no more than, say, 5 seconds.

I'll send more details off-list,

> Thanks in advance.
> karl heinz
> On Tue, Mar 11, 2008 at 5:26 AM, Richard Barnes <> wrote:
>> Hi all,
>> Wanted to let folks know about an experiment that some participants from
>> the GEOPRIV working group have put together for this IETF. Using the
>> IETF network infrastructure as a location source, we've set up a
>> location server [1] that offers location information over the HTTP-based
>> HELD protocol [2]. It works like this:
>> +--------+ +-----+ +---------------------+
>> | Client |---HELD----| LIS |-----------| IETF (NetDisco [3]) |
>> +--------+ +-----+ +---------------------+
>> 1. Client submits HELD request
>> 2. LIS queries NetDisco (over an ad-hoc interface) for location of an IP
>> 3. NetDisco returns civicAddress XML for the AP to which the requested
>> IP is connected, e.g.:
>> <civicAddress
>> xmlns="urn:params:xml:ns:pidf:geopriv10:civicAddr">
>> <country>US</country>
>> <A1>Pennsylvania</A1>
>> <A3>Philadelphia</A3>
>> <A6>Market</A6>
>> <STS>Street</STS>
>> <HNO>1201</HNO>
>> <PC>19107</PC>
>> <ROOM>Franknlin 1/2</ROOM>
>> </civicAddress>
>> 4. LIS inserts civicAddress into PIDF-LO into locationResponse and
>> returns to Client
>> The HELD server is written in PHP, and is based on the open-source HELD
>> LIS written by Andrew Co. [4].
>> We have two clients for you to try out:
>> 1. I wrote a small Java application [5] that pulls location from the
>> HELD server and posts it as the status of a Jabber account. For
>> instance, while I was in SIPPING this afternoon, my status was:
>> "
>> Current location:
>> Civic Address:
>> Franklin 1/2
>> 1201 Market Street
>> Philadelphia, PA 19107
>> "
>> Note: This app runs *alongside* your usual Jabber client, as a separate
>> client, so you don't need to change anything about how you use Jabber.
>> Requires Java 1.6.
>> 2. Along with the open-source LIS from Andrew Co, there's Java client
>> library and GUI that shows most of the features in
>> draft-ietf-geopriv-http-location-delivery-05, including the creation and
>> management of location references (URIs that refer to location). You
>> can download it at [6] (Note: (1) you need to download both the client
>> library and the GUI; (2) requires Windows and Java 1.6.)
>> 3. Karl Heinz Wolf from has enhanced the Zap! SIP client so that
>> it will access location and send it out in SIP messages [7]
>> If you do give these tools a try, please send feedback to me and to the
>> GEOPRIV working group list, <>.
>> Thanks a lot,
>> --Richard
>> [1] <>
>> [2] draft-ietf-geopriv-http-location-delivery-05
>> [3] <>
>> [4] <>
>> [5] <>
>> [6] <>
>> <>
>> [7] <>
>> _______________________________________________
>> Geopriv mailing list
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Received on Fri, 04 Apr 2008 10:08:43 -0400

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