Welltech SIPPBX 6200 V.3.1.1 - Manual (Page 63)

Welltech Technology Co., Ltd.
SIPPBX 6200S, 6200GS, 6200N Release 3.1.1
User Guide
- 63 -
Advance:
Figure 6.3-2
Parameter Description:
• UDP Port: The local UDP port on which the SIP service listened.
• Retransmission T1 (ms): T1 determines several timers as defined in
RFC3261. For example, when an unreliable transport protocol is used, a
Client Invite transaction retransmits requests at an interval that start at T1
seconds and doubles after every retransmission. A Client General transaction
retransmits requests at an interval that starts at T1 and doubles until it
reaches T2. (Default Value: 500ms) **.
• Retransmission T2 (ms): Determines the maximum retransmission interval as
defined in RFC3261. For example, when an unreliable transport protocol is
used, general requests are retransmitted at an interval which starts at T1 and
doubles until reaches T2. If a provisional response is received, retransmission
continues but at an interval of T2. (Default Value: 4000ms) **.
• Retransmission T4 (ms): T4 represents the amount of time the network takes
to clear message between client and server transactions as defined in
RFC3261. For example, when working with an unreliable transport protocol,
T4 determines the time that UAS waits after receiving an ACK message and
before terminating the transaction. (Default Value: 5000) **.
• Invite Linger Timer (ms): After sending an ACK for an INVITE final response,
a client cannot be sure that the server has received the ACK message. The
client should be able to retransmit the ACK upon receiving retransmissions of
the final response for inviteLingerTimer milliseconds.
• General Linger Timer (ms): After a server sends a final response, the server
cannot be sure that the client has received the response message. The
server should be able to retransmit the response upon receiving
retransmissions of the request for generalLingerTimer milliseconds.
• Provisional Timer (ms): The provisionalTimer is set when receiving a
provisional response on an INVITE transaction. The transaction will stop
retransmissions of the INVITE request and will wait for a final response until
the provisionTimer expires. If you set the provisionTimer to 0, no timer is set.
The INVITE transaction will wait indefinitely for the final response.