Aastra Telecom 57I 用户手册

Global SIP Settings

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41-001160-00, Release 2.1, Rev 04  

IP Phone Administrator Guide

9

In the "Transaction Timer" field, enter the amount of time, in milliseconds, that the phone allows the 
call server (registrar/proxy) to respond to SIP messages that it sends.
Valid values are 4000 to 64000. Default is 4000.

Note: If the phone does not receive a response in the amount of time designated for this parameter, 
the phone assumes the message has timed out.

10

In the "Transport Protocol" field, select a transport protocol to use when sending SIP Real-time 
Transport Protocol (RTP) packets. Valid values are User Datagram Protocol (UDP) and Transmission 
Control Protocol (TCP), UDP, TCP, Transport Layer Security (TLS) or Persistent TLS. The value 
“UDP” is the default. For more information about TLS, see 

 on 

 and 

Chapter 5, the section, 

.

11

In the " Registration Failed Retry Timer" field, enter the amount of time, in seconds, that the phone 
waits between registration attempts when a registration is rejected by the registrar. 
Valid values are 30 to 1800. Default is 1800.

12

In the " Registration Timeout Retry Timer" field, enter the amount of time, in seconds, that the 
phone waits until it re-attempts to register after a REGISTER message times out.
Valid values are 30 to 214748364. Default is 120.

13

In the " Registration Renewal Timer" field, enter the length of time, in seconds, prior to expiration, 
that the phone renews registrations.

For example, if the value is set to 20, then 20 seconds before the registration is due to expire, a new 
REGISTER message is sent to the registrar to renew the registration.

Valid values are 0 to 214748364. Default is 15.

14

The “BLF Subscription Period” field is enabled by default with a value of 3600 seconds. 

This feature sets the time period, in seconds, that the IP phone resubscribes the BLF subscription 
service after a software/firmware upgrade or after a reboot of the IP phone.
For information about setting the “BLF Subscription Period”, see Chapter 5, the section,

 on 

15

(For Sylantro Servers) The “ACD Subscription Period” field is enabled by default with a value of 
3600 seconds. 

This feature sets the time period, in seconds, that the IP phone resubscribes the BLF subscription 
service after a software/firmware upgrade or after a reboot of the IP phone.
For information about setting the “ACD Subscription Period”, see Chapter 5, the section,