DTMF Type

DTMF Type
1. MFIM currently support only INFO type DTMF for SIP Extension (does not INBAND and
2833).
☞ for SIP Trunk, all type of DTMF is supported.
2. If SIP Extension talking voice path is connected directly each other then they can implement INBAND or 2833 DTMF independently.
3. Synchronization between system and SIP Phone is required.
- SIP Data / SIP Phone Attributes(211) – DTMF Type : One of INFO (default: DTMF RELAY)
- SIP Phone Self Programming - DTMF Type : INFO or a specific INFO type if there is in select list.
4. By Provisioning for LG-Ericsson SIP Phone, DTMF Type of Phone is automatically set to INFO Type. In that case, you do not need to set it by SIP Phone Self Programming.
Network Related Configuration
1. MFIM IP address for WAN is different from original IP address for LAN
- Condition 1 : MFIM has firewall IP address or MFIM is port-forwarded by VOIM WAN-U or other Switches
- Condition 2 : There is a SIP Phone in WAN side of MFIM
- Resolution : SIP Data / SIP Phone Attributes(211) – Same Zone with MFIM - OFF
- Implementation : MFIM will implement signaling with its WAN IP address for the SIP Phone.
2. A SIP Phone is on NAT environment (for example, wireless SIP Phone via AP)
- Condition 1 : The NAT IP address or IP Port of SIP Phone (WAN address of SIP Phone) is frequently updated.
- Condition 2 : Sometimes communication is disconnected, unreachable or mismatched because of so-often updated address by NAT mapping implementation.
- Resolution 1 : Enable the Keep Alive option for the SIP Station(s) that are on NAT environment.
- Implementation 1: MFIM will send ‘OPTIONS’ message so often (in 30 seconds) to assist to maintain the address of SIP Phone’s WAN.
- Resolution 2 : set static NAT address mapping by port-forwarding. For example 1 to 1 static NAT address assignment by port-forwarding in NAT switch.
- Implementation 2: SIP Phone’s WAN address will not be changed.