19
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 OmniTouch 4135 IP uses the appropriate protocol even if
you have set the phone to use UDP.
Protocol
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 authentication, this is still a rather secure
solution.
SIPS
(
Secure SIP
) is a security measure that uses TLS to provide an
encrypted end-to-end channel for the SIP messages. To use SIPS,
however, both VoIP devices and the SIP server must support it.
L
&WFOJG5SBOTQPSUJTTFUUP5-4PS4*14UIF0NOJ5PVDI*1TUJMMBDDFQUTJODPN
-
ing UDP or TCP signalling.
On phone:
MENU
>
SETTINGS
>
ADVANCED
> (PIN) >
ACCOUNTS
>
TRANSPORT
(6,2,1,3).
SETTINGS