Specifications

MBG Engineering Guidelines, Release 8.0

Bandwidth Required Hourly Usage (100%) Monthly Usage (100%)

Signaling (MiNet) 1 KB/minute 60 KB 43.2 MB

Signaling (SIP) 1.75 KB/minute 105 KB 75.6 MB

G.711 voice stream (IP),

20ms

80 kbps 36 MB 25.92 GB

G.729a voice stream (IP),

20ms

24 kbps 10.8 MB 7.78 GB

Table 2: Bandwidth usage vs time for an IP or SIP phone

Note: 20ms is the default RTP frame size, but the value is configurable in the Mitel Border Gateway

administration panel.

The data in the above table can be used to:

1. estimate the available call time given a quota

2. estimate the monthly bandwidth requirement for a given call volume

Example 1: Estimating Available Call Time

Given an ISP quota of 2 GB/month and continuous use:

Call hours of G.729a = (2000 MB - 43.2 MB) / 10.8 MB per hour = 181 hours

Call hours of G.711 = (2000 MB - 43.2 MB) / 36 MB per hour = 54 hours

Given the same 2 GB/month quota, and usage of 15 min/hr, 12 hours per day, 7 days per week:

Call hours of G.729a = (1448 hours or more than 1 month)

Call hours of G.711 = (432 hours or roughly 18 days)

Example 2: Estimating Monthly Bandwidth Requirements

Given a user that averages 4 hours of phone calls per day, for 22 workdays in a month:

Bandwidth Usage for G.729a = 43.2 MB + (10.8 MB x 4 hr per day x 22 days) = 994 MB

Bandwidth Usage for G.711 = 43.2 MB + (36 MB x 4 hr per day x 22 days) = 3200 MB or 3.2 GB

Configuring the Remote Site Firewall

If the remote office has a firewall, it must be configured to allow the IP or SIP phone to connect through it to the

Mitel Border Gateway. The simplest approach is to permit all connections to or from the MBG's IP address. A

second very simple approach is to permit all outgoing connections and any responses to them. By default, most