Panasonic Kx Tda5480 Getting Started Manual

							Getting Started 51
Appendix A
Guidance for VoIP Installation 
						

							A1 VoIP Requirements
52 Getting Started
A1 VoIP Requirements
A1.1 Bandwidth Assessment
To establish a VoIP network, you must ensure that the network has enough bandwidth to 
support VoIP communications. Inform your network administrator of the required bandwidth, 
and make sure that the network can support VoIP communications even under conditions of 
maximum network traffic.
Bandwidth Calculation
Provided below is the formula to find out the amount of bandwidth required for VoIP 
communications:
Required bandwidth for fax and voice communications for one VoIP channel is shown in the 
tables below (for more details, refer to 2.2.3 Voice Communication Parameters in the VoIP 
Gateway Card Programming Guide).
Required Bandwidth for Voice Communication
Via LAN
Via WAN (PPP: Point-to-Point Protocol)Required Bandwidth
= (No. of Fax Machines × Required Bandwidth for Fax Communication) +
[(4 - No. of Fax Machines) × Required Bandwidth for Voice Communication]
CODECPacket Sending Interval
20 ms 30 ms 40 ms 60 ms 90 ms
G.711 87.2 kbps 79.5 kbps 75.6 kbps——
G.729A 31.2 kbps 23.5 kbps 19.6 kbps——
G.723.1 5.3 kbps—20.8 kbps—13.1 kbps 10.5 kbps
G.723.1 6.3 kbps—21.9 kbps—14.1 kbps 11.6 kbps
CODECPacket Sending Interval
20 ms 30 ms 40 ms 60 ms 90 ms
G.711 84 kbps 77.3 kbps 74 kbps——
G.729A 28 kbps 21 kbps 18 kbps——
G.723.1 5.3 kbps—18.7 kbps—12 kbps 9.8 kbps
G.723.1 6.3 kbps—19.7 kbps—13.1 kbps 10.8 kbps 
						

							A1 VoIP Requirements
Getting Started 53
Required Bandwidth for Fax Communication
Via LAN
Via WAN (PPP: Point-to-Point Protocol)
Example
Consider the following case as an example:
Communication: via LAN
No. of Fax Machines: 1
Required Bandwidth for Fax Communication: 75.6 kbps
Required Bandwidth for Voice Communication: 23.5 kbps
In this case, the required bandwidth will be as follows:
Therefore, inform your network administrator and make sure that the network can support a 
bandwidth of 146.1 kbps even when the network is under conditions of maximum traffic.
Note
It is recommended that all VoIP Gateway Cards in a VoIP network have the same packet 
sending interval.
A1.2 Network Configuration
You must evaluate the structure of the existing network to see if a VoIP network can be 
implemented. Below are the points that should be taken into your evaluation.
Is the IP network a managed network?
A VoIP network should be implemented on a managed IP network such as Frame Relay, 
Leased Line, or IP-VPN (Virtual Private Network).
An unmanaged network—that is, the Internet—cannot be used to employ a VoIP network 
because delays and loss in data transmission can cause huge degradation in speech quality.FAX High Reliable MethodG.711 Packet Sending Interval
20 ms 30 ms 40 ms
Don’t Use 87.2 kbps 79.5 kbps 75.6 kbps
Use 224.8 kbps 213.9 kbps 208.4 kbps
FAX High Reliable MethodG.711 Packet Sending Interval
20 ms 30 ms 40 ms
Don’t Use 84 kbps 77.3 kbps 74 kbps
Use 221.6 kbps 211.7 kbps 206.8 kbps
Required Bandwidth
= (1 × 75.6) + (3 × 23.5)
= 146.1 
						

							A1 VoIP Requirements
54 Getting Started
Is it possible to have static IP addressing?
Because the maintenance of the VoIP Gateway Card is carried out from a personal computer 
(PC) through an IP network, the card must be assigned a static IP address.
Static IP addressing must be made possible even when the DHCP feature is used. For more 
details, refer to 2.2.1 Network Parameters in the VoIP Gateway Card Programming Guide.
Is network address translation (NAT/NAPT) disabled?
In a network where address translation techniques (e.g., NAT/NAPT) are used to convert 
between global and local IP addresses, VoIP communications based on the H.323 protocol 
cannot be carried out appropriately. Generally, NAT/NAPT are features that are available with 
routers.
Note
If the router on the network supports the H.323 NAT feature, it may be possible to have 
VoIP communications over the network. For more information, consult your network 
administrator.
Router
(NAT/NAPT enabled)
IP Network
Global IP Address Domain
Local IP Address Domain 
						

							A1 VoIP Requirements
Getting Started 55
Does only a single router provide access to the IP network?
In a dual network, two routers provide access to the IP network as shown in the diagram below. 
However, the VoIP Gateway Card cannot take the advantage of having two routers as access 
points to the IP network.
For example, if router A, whose IP address is assigned as the default gateway IP address of 
the card, fails, VoIP communications are no longer possible; the card is not able to switch its 
default gateway from router A to router B to access the IP network. For more details about the 
default gateway setting, refer to 2.2.1 Network Parameters of the VoIP Gateway Card 
Programming Guide.
IP Network
Router A Router B
Default gateway 
of the card: 
Router A 
						

							A1 VoIP Requirements
56 Getting Started
Is there only a single IP network between two ends of a call?
A huge degradation in speech quality will be produced when calls are made through multiple 
IP networks as shown below; therefore, it is recommended that you avoid establishing a VoIP 
network in this fashion.
IP Network 1IP Network 2
PSTN
IP Network 1IP Network 2 
						

							A1 VoIP Requirements
Getting Started 57
Is the card located appropriately?
Transmission delays can cause pauses and loss in VoIP communications. The more network 
devices (e.g., routers and switches) there are between the communicating cards, the larger the 
transmission delays, because a certain amount of delay is inevitable when packets go through 
each network device (hop).
One preventative measure is to install the card so that the number of transmission hops is kept 
to a minimum. In the diagram below, the card is located as close to the IP network interface as 
possible.
A1.3 Network Devices
You must evaluate the network devices that are used in the existing network to see if a VoIP 
network can be implemented. Below are the points that should be taken into your evaluation.
Can the firewall pass packets from the VoIP Gateway Card?
If the VoIP network contains a firewall, the firewall must be configured appropriately to allow 
VoIP packets, which are listed in the table below, to pass through the network without being 
blocked by filtering.
For more information, consult your network administrator.
Protocol TCP/UDP Default Port No.
HTTP
*1TCP 80
RTP/RTCP
*2UDP 5004 to 5011
H.225.0 Call Signaling
*2TCP 1720
H.245
*2TCP 1712 to 1724
H.225.0 RAS
*2UDP 1719
*1 For the actual setting values, refer to 2.2.2 H.323 Parameters in the VoIP Gateway Card 
Programming Guide.
Router
Switch Too many hops
Switch
HubRouter
SwitchBetter
(PBX located nearest IP network access point)
Switch
Hub 
						

							A1 VoIP Requirements
58 Getting Started
Are layer 2 or higher switches used?
Use of repeater hubs can increase the network load, and therefore may result in degradation 
in speech quality.
To ensure the performance, it is strongly recommended that you use layer 2 or higher switches.
Are category 5 (CAT 5) cables used?
When connecting network devices, make sure to use CAT 5 cables. If other types of cables are 
used, communications may not be carried out normally.
A1.4 QoS (Quality of Service)
Some routers permit the configuration of priority control features. This allows the router to give 
higher priority to voice packets and lower the rate of loss and delays during transmissions, 
hence improving speech quality. It is strongly recommended that you use this feature, 
especially in networks where traffic is heavy.
Typically, a router identifies what packets to pass in priority by checking the value in the ToS 
field of the header of IP packets. The VoIP Gateway Card has the ability to set the ToS field of 
outgoing voice packets (see 2.2.3 Voice Communication Parameters in the VoIP Gateway 
Card Programming Guide). When the card is appropriately configured, the router can give 
voice packets from the card higher priority.
Consult your network administrator when setting the ToS field, as the setting value must 
conform to the router’s specifications.
Note
Some switches also permit the configuration of priority control features. For more 
information, consult your network administrator. *2 For the actual setting values, refer to 2.2.1 Network Parameters in the VoIP Gateway 
Card Programming Guide. 
						

							A2 VoIP Requirements Checklist
Getting Started 59
A2 VoIP Requirements Checklist
Use the following checklists to see if you can implement a VoIP network. The answers identified 
in underlined bold-face letters
 are the required answers for the corresponding questions.
Bandwidth Assessment
Network Configuration
No. Question Answer Memo Ref.
1Does the network have enough 
bandwidth to support VoIP 
communications?
Make sure that there is more bandwidth 
available for VoIP communications than the 
amount actually required. Ye s
 NoIP network bandwidth
= kbps
Available bandwidth for VoIP
= kbps
Required bandwidth for VoIP
= kbpsp. 52
No. Question Answer Memo Ref.
2-aIs the IP network a managed network?
Make sure to use a managed IP network 
such as Frame Relay, Leased Line, or IP-
VPN (Virtual Private Network). The VoIP 
Gateway Card is not intended for use on 
the Internet. Ye s
 NoType of IP network:
p. 53
2-bIs it possible to have static IP 
addressing? Ye s
 Nop. 54
2-cIs network address translation (NAT/
NAPT) disabled? Ye s
 Nop. 54
2-dDoes only a single router provide 
access to the IP network? Ye s
 Nop. 55
2-eIs there only a single IP network 
between two ends of a call? Ye s
 Nop. 56
2-fIs the card located appropriately? Ye s
 NoNo. of hops (routers/switches) 
within one location:
p. 57 
						

							A2 VoIP Requirements Checklist
60 Getting Started
Network Devices
QoS (Quality of Service)
No. Question Answer Memo Ref.
3-aCan the firewall pass packets from the 
VoIP Gateway Card?
When a firewall is used, make sure to 
configure the firewall appropriately to allow 
VoIP packets to pass through the network 
without being blocked by filtering. Ye s
 NoModel of the firewall:
p. 57
3-bAre layer 2 or higher switches used?
Do not use repeater hubs as they can 
increase the network load. Ye s
 NoModel of the switch:
p. 58
3-cAre category 5 (CAT 5) cables used? Ye s
 Nop. 58
No. Question Answer Memo Ref.
4Can the router or switch be configured 
to use priority control features? Ye s
 NoModel of the router/switch:
VoIP Gateway Card’s ToS field 
setting:p. 58