[Serusers] Enum as location-database

[Andreas Granig]

Soren (Home) wrote:
> I don't really understand the advantage, but it is something like you want
> to share the locations between different instances of SER?  (and not just
> by sharing the database)

First of all I want to use enum for peering partners who want to route 
their calls over our PSTN gateways. These entries can be inserted when 
new numbers are allocated and removed when they are released by our 
peering partners via a defined interface.
This is a quite straight-forward task and only requires SER to query the 
database.

But theoretically I could also insert "real" locations, which could be 
used for looking up numbers with phone extensions.

My current situation is that I have UACs that connect to ISDN PBX. The 
UAC registers with 012345 at 1.2.3.4 and behind the PBX there exists the 
phone extension 1000.
Now someone calls 0123451000 at my.domain, a does_uri_exist() returns 
false. So I have to strip down the number to the base number 012345, for 
which I can look up the location. The problem is that the URI now is 
sip:012345 at 1.2.3.4 instead of sip:0123451000 at 1.2.3.4
Now I could implement my own lookup-function which keeps the user-part 
and replaces only the host-part with the IP of the registered base number.

But since I want to use enum anyway, I thought that I could use enum 
also for this scenario, because with enum I could insert 
wildcard-locations and use regexps, so that 012345.*@my.domain always 
resolves to 012345.*@1.2.3.4

> Locations can change rapidly, while I would think of ENUM as "semi"-static
> information. Typically DNS takes atleast some few hours to spread,
> however, It could be different if you are using local DNS-server (w/o
> cache) and point your resolv.conf to it.

Right, it's just a local noncaching DNS server.

Andy