subscription keeps ending after new Subscription is added

[ChhitizShrestha]

We have multiple users login in into our system. Where we subscribe to Broadsoft call events.
First user that logs in everything works fine. All the calls are represented fine. 
When Second User logs in sometimes the first user's subscription is terminated, sometimes second users subscription is terminated. but both the subscription is not working simultaneously.

What are the reasons that could trigger SubscriptionTerminatedEvent.

[skumar1 · Accepted solution]

Could you send a sip trace for the reported issue?

[ChhitizShrestha · Accepted solution]

I  am sending This as an subscription Body. Are there any restrictions as applicationId should be unique or not. Or any other Restriction that can terminate my subscription.
Currently I am using a live environment which is not under our control and hence don't have access to SIP log.

<?xml version="1.0" encoding="UTF-8"?>

<Subscription xmlns="http://schema.broadsoft.com/xsi">    

    <event>Advanced Call</event>

    <expires>3600</expires>

    <httpContact>        

        <uri>url/Broadsoft/PbxStatus/${CustomerGUID}/${UserGuid}</uri>

    </httpContact>

    <applicationId>ABC {UserGuid}</applicationId>

</Subscription>