GoJS 1.7 has been released as the latest stable version.
Can I add custom shapes for the link other then the bezier curve?
For example in the above, I have text between the two connections.
Are you asking about https://gojs.net/latest/intro/linkLabels.html ?
Yes, something on the same lines but if the length of the link increases, I want it to be repeating after some distance. I want to highlight/name the connection between two nodes. For e.g. below
If your lines will only be horizontal, then you could use a Pattern Brush: https://gojs.net/latest/intro/brush.html#PatternBrushes
If you want the text to be drawn repeatedly along the path of the link, then you could set the Shape.pathPattern, as shown in https://gojs.net/latest/samples/relationships.html. But the pattern, the TextBlock in your case, will be drawn without any gaps between them. There is no way to only draw the text at intervals. Sorry.