Difference between DefaultMessageTimeToLive theme and DefaultMessageTimeToLive subscription on Azure Service Bus

Question

Both the Azure Service Bus Theme and associated Subscription expose property DefaultMessageTimeToLive; initialized like this:

if (!NamespaceManager.TopicExists(TopicName))
{
    NamespaceManager.CreateTopic(
        new TopicDescription(TopicName)
            {
                MaxSizeInMegabytes = 5120,
                DefaultMessageTimeToLive = TimeSpan.FromDays(14)
            });
}

if (!NamespaceManager.SubscriptionExists(TopicName, SubscriptionName))
{
    NamespaceManager.CreateSubscription(
        new SubscriptionDescription(TopicName, SubscriptionName)
            {
                LockDuration = TimeSpan.FromMinutes(5),
                DefaultMessageTimeToLive = TimeSpan.FromDays(7),
                EnableDeadLetteringOnMessageExpiration = true
            });
}

What is the difference between the two and what is the purpose of the two TTL settings? Moreover; If the message expires in the Subject , what happens to it?

Answer 1

TTL, , . TT, , , TTL. TTL, , , , TTL, , TTL. , DeadLettering , messaged DeadLetter, .

: http://msdn.microsoft.com/en-us/library/windowsazure/hh780749.aspx