Scenario:  Call transfer between 3 phonerlite softphones

From Instance 1 make calls to instances 2 and 3 and accept them.
Drop one of the active calls onto the other.
Instance 1 correctly generates a refer message using the replaces header.

The Recipient of the refer constructs an INVITE with an R-URI containing a replaces header extracted from the refer.
Unfortunately the R-URI doesn't contain the to and from tags sent in the refer. (These are however added to the TO header)

Symptom:
The recipient of the INVITE containing the replaces header fails to recognise this as a replaced call.