Using shared channels will ensure the best possible Teams sharing experience between Ithaca and Cornell Tech, Weill Cornell Medicine, and Weill Cornell Medicine-Qatar.

Create Shared Teams Channels

Initial team setup

This will create a host team in your home instance of either Ithaca and Cornell Tech, Weill Cornell Medicine (WCM), or WCM-Qatar. Your home instance is also referred to as your host Team.

1. Click Teams on the left side of the app, then click the plus icon (mouse-over displays Create and join teams and channels) at the top of your teams list.
2. Select Create team. Options to Create a team from a template will display in the main portion of the app.
3. Click Other. The Other window will display.
4. Click Use this template on the bottom right of the window. The What kind of team will this be? window will display.
5. Click Private.
6. Enter a Team name and Description, then click Create in the bottom right of the window. Microsoft Teams may take a minute to finish creating the team and loading before an Add members window will display.
7. Enter a name or email to add at least one other team owner. Do not add anyone besides team owners at this time. Other members will be added to the shared channel or channels later.
8. Select Owner from the dropdown list next to each member. Team owners must be part of the host team, meaning WCM or WCM-Qatar staff cannot be an owner of a team hosted in Ithaca's instance of Teams and vice versa.
9. Click Add to finish creating the team.

Create a shared channel and add members

In addition to setting team ownership, each shared channel will need to have owners added to it individually. Ownership will not carry over from the team ownership assignments. Creating a shared channel will allow you to add anyone from your host team or individuals from another Teams instance.

1. Click the three-dot icon next to the team, then select Add channel. The Create a channel window will display.
2. Enter a Channel name and Description. When choosing a Channel name and Description, help members understand what it is and who is using it. For example, if you have some shared channels open to everyone on the project, but other shared channels that are only for certain members, you could add (private) at the end of the channel name designated for only certain members. This provides an idea of who can see the contents of the channel. 
3. Click the Choose a channel type dropdown menu, then select Shared. By default, there will be a a check next to Share this channel with everyone on the team. If you don't want to share the channel with your team—or you only want to share with specific people—uncheck it.
4. Click Create in the bottom right of the window. The channel will be added to the team, and you will be prompted to share the channel by adding people. At this time, only add people you wish to be channel owners. Do not add regular members yet.
5. Enter a name or email to add channel owners, then click the dropdown arrow next to each member and select Owner to make them an owner.
6. Click Share in the bottom right of the window when you have added all of the channel owners.
7. Before adding regular members, make a welcome post in each shared channel explaining the purpose of the channel and who its audience is. For example, a post can indicate this shared channel is open to everyone on the project or maybe it is restricted to only directors.
8. Add members to the shared channel.

About the General channel

The General channel is always part of every team, however, it cannot be shared between campuses. For this reason, the instructions on this page result in only team owners being able to see the General channel. The people who are added as individual members to your shared channels cannot see the General channel.

Turn on Channel Moderation for the General channel, so only Team Owners can post in the channel. This setup helps prevent others from mistakenly posting there while expecting that shared channel members can also see it.

Change moderator roles and settings in a channel in Microsoft Teams - Microsoft Support

Once you enable moderation, post in the General channel explaining to others that that channel is locked, and they should use the shared channels.

Consider also creating a shared channel dedicated to discussions about changes to the team. This may include only team owners or could include additional members. The space could be used to discuss the need for new channels or adding/removing members.

More advanced configurations

Quickly add all members in the same instance as you to shared channels

If you are adding the same members who are in the same instance as you to many shared channels, this process can save time.

You can add members to the team itself. (This only applies to members of the host team. For example, do not add WMC or WMC-Qatar members to the an Ithaca or Cornell Tech-hosted team or they will be added as guests, which is a separate account and can cause confusion.)

When creating a shared channel, ensure the box is checked that says Share this channel with everyone on the team. This will give all members of the team access to the shared channel.

You will still need to add external members to the team individually as outlined in Create and share channels above.

If you add members from the same instance as you at the team level, it's very important to enable Channel Moderation on the General channel. This will prevent members in your same instance from posting in the General channel while expecting members from another instance to see it.

Allow someone outside the host team to manage access with another team

This can be helpful to manage who can access a shared channel. You can choose to share a channel with a team, at Ithaca or Cornell Tech and at WCM or WCM-Qatar, then that team owner can add/remove members.

1. Create your team and shared channel as above.
2. Your counterpart in the other instance will create their own team.
3. Share a channel with a team
4. When prompted, enter your counterpart’s email address.
5. They will receive your invitation and can choose to add the shared channel to their team.
6. You will receive a notification to approve the team they added the shared channel to.
7. Anyone they add to their team will have access to the shared channel. You will not need to manage the membership of their users.