There is a big latency with JIRA and it is affecting the performance. Why is it so slow? I have looked into our network and its not an issue. Something with the URL?

[Nic Brough -Adaptavist-]

It's most likely to be the connection from the US data centres to your clients than anything else.

However, start by defining "slow" - is it page loads?  Javascript?  etc?  Are there patterns like time (e.g. always runs slow at 3pm), user activity (reading stuff is fine, bulk-edits are slow) or is it the same constantly?  And so-on.