Blocking is an idea, but as you're basically doing a an SS7 query to the remote operators HLR it's possible the HLR may not respond or take a little while to respond. That's where caching comes into play.
Indeed. I think if you are planning on caching at your end, then you need to provide users with a way to force a live get as well, possibly making this a higher cost, or more to the point the cached one cheaper :-)
Ben
