I am in the UK-my regular golfing partner on xbox in the US, suddenly can't play a game with him, can't private chat or join xbox party. Any suggestions?

Hmm don't sound like a router issue, to completely rectify that theory I would bypass the router and run your modem directly in the Xbox network port and see if you have the same issues.

Depending on which type of chat session you are connected to... everyone needs to be in the same chat menu. Sometimes when switching from game chat to party chat you might still be stuck in game chat while others are in private chat or visa versa.

To talk to only players in your game: Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat.

To talk to only members of the party: Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat.

To mute an individual: Press the Guide button, then select Party, the player's gamertag, and Mute.

It is a possibility that you are not in the same chat session with your friends. they might be in a party chat with others while you are in game chat. (note you can only have a max of 8 people in one party chat) Or you might still be in a party chat (that everyone else has left) and they are in game chat.
To... Do this... Talk to only players in your game Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat. Talk to only members of the party Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat. Mute an individual Press the Guide button, then select Party, the player's gamertag, and Mute.
To... Do this... Talk to only players in your game Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat. Talk to only members of the party Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat. Mute an individual Press the Guide button, then select Party, the player's gamertag, and Mute.
To... Do this... Talk to only players in your game Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat. Talk to only members of the party Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat. Mute an individual Press the Guide button, then select Party, the player's gamertag, and Mute.
Key Points

• Online safety and privacy settings may block access to Xbox LIVE chat.
• To use Xbox LIVE parties and chat, Voice and Text must bet set to Friends or Everyone

To... Do this... Talk to only players in your game Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat. Talk to only members of the party Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat. Mute an individual Press the Guide button, then select Party, the player's gamertag, and Mute. To... Do this... Talk to only players in your game Press the Guide button, then select Party, Party Options, Chat Channel, and Game Chat. Talk to only members of the party Press the Guide button, then select Party, Party Options, Chat Channel, and Party Chat. Mute an individual Press the Guide button, then select Party, the player's gamertag, and Mute.

is your NAT type open or strict. if strict call your internet service provider and find out how to change that, as i had the same problem.

Here are instructions on using private chat when playing a game:

http://support.xbox.com/support/en/us/xbox360/xboxlive/xboxlivecommunity/chat/chat.aspx

Hope this helps!

You should still be able to play online with people, as the party privacy only effects parties that YOU make. If you join a playlist, you should be able to join in on the fun :)

Lemme know if you need any more help
BB

That happens when other people join the party and leave before its done loading and there aren't enough players to play the game. It happens all the time with games like Halo 3 and RainbowSix.

you need to assign a static ip address to each inside your router they are more than likely using the same ip address

The case is the way the network is setup are you connecting him via a router? Make sure your NAT is open on the router as well.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/edwy_1a56970cf1ea4620

your nat type is strict you can change this by opening up your internet explorer go to tools then internet options and make the needed changes

This problem is not uncommon, it is that your NATs are different, you can configure your internet settings, to do this, just look up on google how to configure your NAT.