We recently deployed exhcange 2007 and microsoft's unified messaging. The UM servers and SIP gateways are located in our central office. The remote office have their own exchange servers. Our issue is that when a user calls in to listen to their voicemail they get a "perculator" or "static" sound if they have a large amount of outlook contacts. What this is caused from is that when the voicemail is listened to the GAL is queried and also the users personal contacts to relate the extension to a persons name. This works fine over the WAN UNTIL you have users with 200 or more contacts roughly. At that point the user hears strange noise while it is doing the lookup and it takes awhile.
1. Can we turn the lookup off so it doesn't associate at all with a name? We haven't found a way of doing this.
2. It will cost us 13,000 to place SIP gateways in all offices and the other option of centralizing all users works to fix this issue but that project will take awhile. What are others doing in this scenario, we've though of QoS, wondering if there are other options or config changes to check?
Please feel free to ask many questions, I know this topic is hard to explain over a forum post.