NEC ELECTRA ELITE IPK II, User Manual

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Document Revision 4C Electra Elite IPK II
2 - 532 IP Station (MEGACO) – IAD (Integrated Access Device)

NAT Beater – Network Address Translation
For this feature, the IAD(8)-U( ) ETU is installed and assigned as an ESI(8)-U( ) ETU. Each IAD(8)-U( )
ETU supports up to eight IP Phones and reduces the maximum capacity of stations in the system by
eight.
A maximum of 14 IAD(8)-U( ) ETUs can be installed supporting the maximum of 112 stations (refer to
Table 2-44 KSU Power-Based Calculator Chart on page 2-1044 in the Universal Slots feature).
The IAD(8)-U( ) supports only those vocoders that are approved to provide toll-quality speech path. The
following voice compression methods are supported for the IP Station (MEGACO) application:

G.711

Law – Highest Bandwidth

G.729 – Mid-Range Bandwidth
Each voice call requires at least the specifications listed in the following table. This includes all the
overheads of VoIP communication, including signaling).

The IAD(8)-U( ) ETU contains a regular TCP/RTP/IP stack that can handle real time media. The
IAD ETU is an end-point on the IP network from the network administration perspective.

The IAD(8)-U( ) ETU uses MEGACO (H.248) Protocol to provide telephony services between
remote stations through the IP Network. This is an IETF/ITU standards-based protocol. Currently,
this protocol does not natively allow communications across networks where Network Address
Translation (NAT) is performed.

Speech-connection audio quality depends greatly on the available bandwidth between the stations
in the data network. Because Internet is an uncontrolled data network compared to an Intranet,
using this application in Intranet WAN environment with known (or controlled and assured) Quality
of Service (QoS) is highly recommended.

When any network where the IAD(8)-U( ) ETU or any of its IP terminals is connected uses NAT for
connecting the voice calls (including firewall), consulting your network provider/administrator to
specifically request service for VoIP or real-time media support on your networks is recommended.

A static IP Address is required for each IAD(8)-U( ) ETU in the network.
Codec
Transmit
Data Rate
Receive
Data Rate
Time
Between
Packets
Packetization
Delay
Default Jitter
Buffer Delay
Theoretical
Maximum
MOS
G711

Law 90 Kbps 90 Kbps 20 ms

1.5 ms 2 datagrams
(40 ms)
4.4
G729 34 Kbps 34 Kbps 20 ms

15.0 ms 2 datagrams
(40 ms)
4.07

When an IP Soft Phone is connected, set Time Between Packets to 100 ms.