As per RFC 3261, SIP Trapezoid

UAC1 - INVITE - UAS1 UAS1 - INVITE - UAS2 UAS1 - 100 Trying - UAC1

But i tried to check logs in SER which shows

UAC1 - INVITE - UAS1 UAS1 - 100 Trying - UAC1 UAS1 - INVITE - UAS2

Why is it different.

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