Multi-Tech Systems MVP103 ユーザーズマニュアル

Chapter 3 – Related MultiVOIP Setup Parameters 

 

Multi-Tech Systems, Inc. Avaya Communication Manager Guide  

35 

Communication Manager Parameter Definitions (cont’d)

 

RAS Time to 
Live 

Numeric 
(in seconds) 

The MultiVOIP sends this value to CM in the Registration Request 
(RRQ). However, the MultiVOIP will send “Keepalive” RRQs based 
on the TTL received from CM during Registration Confirm (RCF)

Enable 
Survivability 
Mode 

Y/N 

Enable/disable MultiVOIP’s Gateway Survivable mode wherein 
MultiVOIP manages its own IP traffic using its inbound and 
outbound phonebooks in the event of failure of the primary, alternate 
#1 and #2 gatekeepers (if alternates are present). 

Switching 
Time Interval 

numeric 
(in seconds) 

When MultiVOIP is in “gateway” survivable mode meaning the 
Communication Manager gatekeeper to which it is registered failed 
(along with any alternate gatekeepers providing redundancy), the 
MultiVOIP manages IP phone traffic with its own phonebooks.  It 
will seek to return to being controlled by the Communication 
Manager gatekeeper.  The Switching Time Interval determines how 
often it will seek to restore its registration with the primary 
Communication Manager gatekeeper.

H.323 Version 4 Parameters

Q.931 
Multiplexing 
(Mux)  

Y/N 

Signaling for multiple phone calls can be carried on a single port 
rather than opening a separate signaling port for each call.  This 
conserves bandwidth resources. 
If 

 is enabled, this 

field defaults to “Y” for FXO/DID ports and to “N” for FXS ports 
and it cannot be changed. 

H.245 
Tunneling 
(Tun)

  

Y/N

 

H.245 messages are encapsulated within the Q.931 call-signaling 
channel.  Among other things, the H.245 messages let the two 
endpoints tell each other what their technical capabilities are and 
determine who, during the call, will be the client and who the server. 
Tunneling is the process of transmitting these H.245 messages 
through the Q.931 channel. The same TCP/IP socket (or logical port) 
already being used for the Call Signaling Channel is then also used 
by the H.245 Control Channel. This encapsulation reduces the 
number of logical ports (sockets) needed and reduces call setup time.
If 

 is enabled, this 

field defaults to “Y” for FXS and FXO ports and cannot be changed. 

H.323 Version 4 Parameters

Parallel H.245 
(FS + Tun)

  

Y/N

 

FS (Fast Start or Fast Connect) is a Q.931 feature of H.323v2 to 
hasten call setup as well as ‘pre-opening’ the media channel before 
the CONNECT message is sent.  This pre-opening is a requirement 
for certain billing activities.  Under Parallel H.245 FS + Tun, this Fast 
Connect feature can operate simultaneously with H.245 Tunneling 
(see description above). 
If 

 is enabled, this 

field defaults to “N” for FXS and FXO ports and cannot be changed. 

Annex –E (AE)

  

Y/N

 

Multiplexed UDP call signaling transport.  Annex E is helpful for 
high-volumeVOIP system endpoints.  Gateways with lesser volume 
can afford to use TCP to establish calls.  However, for larger volume 
endpoints, the call setup times and system resource usage under 
TCP can become problematic.  Annex E allows endpoints to perform 
call- signaling functions under the UDP protocol, which involves 
substantially streamlined overhead.  (This feature should not be 
used on the public Internet because of potential problems with 
security and bandwidth usage.) 
If 

 is enabled, this 

field defaults to “N” for FXS and FXO ports and cannot be changed.