what is the difference between application links and application tunnel

[Rasajna Meka]

what is the difference between application links and application tunnel. Will application tunnel support non-atlassian self hosted applications?

[Rilwan Ahmed]

Hi @Rasajna Meka ,

Application links (sometimes called app links) allow you to set up links, share information, and provide access to certain resources or functionality across multiple Atlassian products. 

Application tunnel is used to connect Atlassian Cloud products with your server and Datacenter Atlassian instances. 
Example: To create a application link between Jira cloud and Confluence Server, first you need to install application tunnel in confluence server and then create the application link to jira cloud. 

[Rasajna Meka]

Hi @Rilwan Ahmed ,

Thanks for the response. Can't we directly integrate Jira cloud with conflence server  using Application links without Tunnel?

Can I integrate self hosted  non -atlassian applications to Jira cloud using Tunnels?

[Rilwan Ahmed]

Hi @Rasajna Meka ,

1. Can't we directly integrate Jira cloud with conflence server  using Application links without Tunnel? 
-- Yes, you can but you need modifications in the network side to allow connections between Atlassian cloud jira. i.e. you need to allowlist Atlassian Cloud IPS and domains as mentioned in https://confluence.atlassian.com/enterprise/create-application-links-between-cloud-and-self-managed-products-1101925750.html

2. Can I integrate self hosted  non-atlassian applications to Jira cloud using Tunnels?
-- No. Atlassian tunnel needs to be installed in your confluence server or your self hosted Atlassian products only. 

The following products support application tunnels:

Cloud

• Jira Work Management Cloud

• Jira Software Cloud

• Jira Service Management Cloud

• Confluence Cloud

Data Center or Server

• Jira Core / Software 8.8 or later

• Jira Service Management 4.8 or later

• Confluence 7.4 or later

• Bitbucket 6.9 or later

You can  go through the link to know how to integrate Jira cloud with other applications: https://support.atlassian.com/jira-cloud-administration/docs/integrate-jira-cloud-with-other-products-and-apps/

[Ming Zhang]

I understand the application tunnel is mainly for communication between the Atlassian cloud and Atlassian on-prem applications. However, can I integrate Gearset with the Jira Datacenter (on-prem) using an application link via an application tunnel? 

https://docs.gearset.com/en/articles/1384669-integrating-with-jira-hosted-cloud

We just don't want to expose our Jira on-prem instance to the public internet directly. 

Thanks