HMR completely remove Message Body fore BYE and ACK

Session Initiation Protocol (BYE)

Request-Line: BYE sip:7512121@192.168.100.10:5060 SIP/2.0

Method: BYE

Request-URI: sip:7512121@192.168.100.10:5060

Message Header

CSeq: 591501 BYE

Max-Forwards: 70

Content-Length:   171

Content-Type: multipart/mixed;boundary=sonus-content-delim

MIME-Version: 1.0

Message Body

MIME Multipart Media Encapsulation, Type: multipart/mixed, Boundary: "content-delim"

[Type: multipart/mixed]

First boundary: --content-delim\r\n

Encapsulated multipart part:  (application/isup)

Content-Disposition: signal; handling=required\r\n

Content-Type: application/isup; version=itu-t92+; base=itu-t92+\r\n\r\n

ISDN User Part

Message Type: Release (12)

Cause indicators

Mandatory Parameter: Cause indicators (18)

Pointer to Parameter: 2

Parameter Length: 2

Cause indicators (-> Q.850): 8a90

.... 1010 = Cause location: Network beyond interworking point (BI) (10)

.00. .... = Coding standard: ITU-T standardized coding (0x0)