Xinpeng, All, Thanks for putting this together.
It seems that discovery involves two aspects: - Deployment of LoST servers, which also impacts discovery of LoST severs - Protocol (format of messages that is communicated) The current document is placing deployment out of scope, but does suggest that preconfiguration is a strategy. That just leaves the protocol, which, may be characterized as: 1. Device sends request with its location 2. Server responds with a list of (name, uri) pairs Given that this is relatively simple, should we just build it into PAWS protocol itself? For example, the current revision (r05) of the PAWS protocol allows for the following: 1. Device asks database for available spectrum in a location outside the coverage area for the Databae 2. The Database returns OUTSIDE_COVERAGE error and MAY include a list of (name, databaseUri) entries to "recommend" alternate databases This provides almost the same capability. Should we just add a ListDatabase to PAWS? -vince On Thu, May 23, 2013 at 6:57 PM, Weixinpeng <[email protected]> wrote: > Hi Mark,**** > > Please see comments inline. Thanks!**** > > ** ** > > Best Regards,**** > > Xinpeng.**** > > ** ** > > ** ** > > *From:* Mark Jones [mailto:[email protected]] > *Sent:* Thursday, May 23, 2013 10:31 PM > *To:* Weixinpeng; [email protected] > > *Cc:* Peter McCann; Zhulei (A) > *Subject:* RE: [paws] draft-wei-paws-database-discovery-01**** > > ** ** > > Hi Xinpeng,**** > > ** ** > > Thank you for your responses. I have some further comments/questions > inline below (prefixed by mj>).**** > > ** ** > > *From:* Weixinpeng [mailto:[email protected] <[email protected]>] > *Sent:* May-22-13 11:13 PM > *To:* Mark Jones; [email protected] > *Cc:* Peter McCann; Zhulei (A) > *Subject:* RE: [paws] draft-wei-paws-database-discovery-01**** > > ** ** > > Hi Mark,**** > > Thanks for your feedback, and I think there are some issues that > I need to clarify.**** > > **** > > we have to be clear that the discovery mechanism is provided as > an optional method that can help master device to find the correct WSDB, > which means the master device can get WSDB by, such as, pre-configuring of > WSDB, provision etc. **** > > ** ** > > mj> Understood.**** > > ** ** > > The dynamic discovery mechanism provides more convenient for > master device to find WSDB, for example, when a new WSDB is setup for > providing service or when some deployed WSDB goes down and never work.**** > > **** > > mj> In this regard, DNS resolution would appear to be equally convenient > mechanism to manage WSDB instances being commissioned or decommissioned. I > view LoST as a kind of “location-aware DNS” so I understand its > applicability to discovery of the appropriate WSDB. I still think the draft > needs more information on how the Master device finds its WSDB DS so that > implementers understand if/when this optional discovery method is > applicable to their deployment.**** > > *[Wei] Yeah, because we cannot covey location information in DNS query > message, so DNS is inappropriate to find the WSDB. I think I will do more > clarification about how master device finds WSDB DS later.***** > > ** ** > > About the DHCP you mentioned below, technically speaking, there > have been some extension of DHCP for supporting the provision of LoST > server, refer to RFC5223. **** > > ** ** > > mj> I understand that the DHCP option specifying the LoST server would be > provided to the Master device when it initiated its backhaul connection > (non-WS connection) to the internet. Correct?**** > > *[Wei] Yeah.***** > > ** ** > > Besides, using DHCP method doesn’t means IP network provider must have > some business relationship with WSDB DS provider, if the network provider > wants to provide master device with FQDN of WSDB DS it can use DHCP.**** > > ** ** > > mj> If the backhaul network operator is configuring his DHCP server to > send options to provision the WSDB DS then I assume he has some business > interest in doing so. What am I missing?**** > > *[Wei] I think there may be some relationship between network operator > and WSDB DS. But the reason why DHCP is mentioned here is because in the > LoST protocol DHCP is extended to provide LoST server’s domain name to the > LoST client.***** > > ** ** > > Thanks**** > > Mark**** > > ** ** > > Best Regards,**** > > Xinpeng.**** > > ** ** > > *From:* Mark Jones [mailto:[email protected] <[email protected]>] > *Sent:* Wednesday, May 22, 2013 11:29 PM > *To:* Weixinpeng; [email protected] > *Cc:* Peter McCann > *Subject:* RE: [paws] draft-wei-paws-database-discovery-01**** > > ** ** > > Hi Xinpeng,**** > > ** ** > > In section 3, you state:**** > > ** ** > > The URL or IP address of WSDB DS can be found by any method such as**** > > DNS, DHCP, manually configuring etc, and it is out of scope of this**** > > document.**** > > ** ** > > I’m unclear on how the Master device obtains the URL of a trusted > discovery server unless there is some pre-configuration involved. I > understand that DNS could be used if the Master device is already > pre-configured with a preferred/home TVWS DS URL (or a preferred/home > domain that is then resolved with U-NAPTR) but I don’t see how DHCP could > be used to bootstrap this information in the TVWS scenarios. Please could > you elaborate.**** > > ** ** > > Thanks**** > > Mark**** > > ** ** > > ** ** > > *From:* [email protected] > [mailto:[email protected]<[email protected]>] > *On Behalf Of *Weixinpeng > *Sent:* May-21-13 9:11 PM > *To:* [email protected] > *Cc:* Peter McCann > *Subject:* [paws] draft-wei-paws-database-discovery-01**** > > ** ** > > Hi all, **** > > I have uploaded a new version draft on database discovery. > Comments are welcomed.**** > > http://tools.ietf.org/html/draft-wei-paws-database-discovery-01.**** > > ** ** > > ** ** > > Xinpeng Wei**** > > _______________________________________________ > paws mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/paws > > -- -vince
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