Hi all,
it might be a minor issue, or it might not be an issue at all, but I stumbled over
following statements in RFC 3261:
Chapter 16.6 Request Forwarding (of a proxy)
1. Copy request
The proxy starts with a copy of the received request. The copy
MUST initially contain all of the header fields from the
received request. Fields not detailed in the processing
described below MUST NOT be removed. The copy SHOULD maintain
the ordering of the header fields as in the received request.
The proxy MUST NOT reorder field values with a common field
name (See Section
7.3.1<https://www.rfc-editor.org/rfc/rfc3261.html#section-7.3.1>)1>). The proxy MUST
NOT add to, modify,
or remove the message body.
An actual implementation need not perform a copy; the primary
requirement is that the processing for each next hop begin with
the same request.
Chapter 16.7 Response Processing (at a proxy)
9. Forward response
After performing the processing described in steps "Aggregate
Authorization Header Field Values" through "Record-Route", the
proxy MAY perform any feature specific manipulations on the
selected response. The proxy MUST NOT add to, modify, or
remove the message body. Unless otherwise specified, the proxy
MUST NOT remove any header field values other than the Via
header field value discussed in Section
16.7<https://www.rfc-editor.org/rfc/rfc3261.html#section-16.7> Item 3. In
particular, the proxy MUST NOT remove any "received" parameter
On the other hand, everywhere in the Internet (starting with stackoverflow), you can read
it is OK, if a SIP proxy modifies a body, and also kamailio allows it.
Might be a question for the coffee break.
All the best
Christoph