TFTP : Quick Definition
TFTP is the part of Call Manager where you store all phone’s configuration so that you are able to retrieve then at the bootup sequence. TFTP IP Address will be communicated to IP Phones via...
read moreDNS : Quick Definition
DNS is the tool which associate an IP Address with a name, an URL. So using name instead IP Address can also introduce failures because if your DNS down , you can’t resolve anymore IP...
read moreNetwork Address Translation – NAT
To work correctly with your voice flows, a NAT device must inspect Layer3 and Layer4 protocol ,port information and sometimes the embedded payload. Cisco IOS NAT ALG can support the following voip...
read moreFirewalls and Application Layer Gateway – ALG
Firewalls are commonly used to protect networks, including those that transport voice traffic. Firewalls inspect the header and sometimes can inspect also the payload of packets. Stateful firewalls...
read moreTCP/UDP Port List
Here is as a reminder a collection of TCP/ UDP Ports used in an IP Telephony network: PORT PURPOSE TCP/1433 SQL TCP/2552 Call Manager database change notifications TCP/2555 RIS database server...
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