Konftel 300IP Installation Manual page 22

SETTINGS
Advanced
Enable SIP Replaces Default is Yes. Setting this option to No, will instruct the PBX not
Enable Blind Transfer Default is Yes. Setting this option to No, will disable the transfer
Transport
The transport setting only concerns the protocol to be used for SIP messages between the
devices involved. These settings do not include the media (the actual call). The settings
on the Media tab should be set accordingly.
Note that if you choose to use a secure connection, both units must support it. Otherwise
they cannot negotiate a connection. If an incoming call demands a secure TLS or SIPS
connection, the Konftel 300IP uses the appropriate protocol even if you have set the
phone to use UDP.
Protocol
to use the SIP replace header. Some PBXes try to take over the
bridging functionality from Konftel 300IP using this command,
which causes the calls to interrupt.
function (
MENU > TRANSFER
PBX does not support blind transfer.
UDP (User Datagram Protocol) is a protocol on the transport layer
in the Internet Protocol Suite. It is a stateless protocol for short
messages – datagrams. Stateless implies that it does not establish
any connection between sender and receiver in advance. UDP
does not guarantee reliability or ordering in the way that TCP does.
Datagrams may arrive out of order or go missing without notice.
The advantages it offers are speed and efficiency.
UDP is the default protocol for SIP.
TCP (Transmission Control Protocol) is a protocol on the transport
layer in the Internet Protocol Suite. TCP is the standard protocol
for Internet communication. TCP keeps track of all individual
packets of data, ensuring that they reach the receiver and are put
together properly. TCP is not the default protocol for SIP, because
it is slower and uses more bandwidth than UDP.
With UDP and TCP, SIP packets travel in plain text. TLS (Transport
Layer Security) is a cryptographic protocol that provides security
and data integrity for communications over TCP/IP networks. TLS
encrypts the datagrams of the transport layer protocol in use. The
secure connection may be to the end device or to the first server
(usually the SIP server where the phone is registered). There is
no guarantee that there is a secure channel to the end point, but
because the SIP server is the only part receiving the user authenti-
cation, this is still a rather secure solution.
20
) during a call. This may be used if the