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ATL Telecom IP300S User Manual

Page 66

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IP SIP Phone v2 User’s Guide

Mar. 2005

[66/100]

CSeq: 1 INVITE

Contact: "7751" [email protected]:5060>

User-Agent: SIP-Phone/1.1

Content-Length: 171

Content-Type: application/sdp

v=0

o=m000dc300051 0 0 IN IP4 192.168.3.51

m=audio 5102 RTV/AVP 0 8 18

a=ptime:10

z VoIP Bandwidth

Packet rate is especially important for sizing a network against a router because routers

are not only constrained by bandwidth but the number of packets per second (PPS) that they
can process.

This table calculates the bandwidth consumption based on uni-directional voice only. So

for the total bandwidth used for media during a simple two-way call, you should multiply the
value by two.

Link

CODEC

Frame per

RTP Packet

(Packet Rate)

IP

(kbps)

PPP

(kbps)

Ethernet

802.3

Averaged

Band-width

Utilization

Delay

(ms)

Mean

Opinion

Score

(MOS

6

)

1 (35 pps

7

)

16.8

18.4

21.6 28% 37.5

2 (17 pps)

11.2

12

13.6

43.2%

67.5

3 (12 pps)

9.3

9.9

10.9

52.8%

97.5

4 (9 pps)

8.4

8.8

9.6

59.3%

127.5

5 (7 pps)

7.8

8.2

8.8

64.1%

157.5

G.723.1
5.3 kbps

6 (6 pps)

7.5

7.7

8.3

67.7%

187.5

3.5-3.7

1 (35 pps)

17.9

19.5

22.7

31.9%

37.5

2 (17 pps)

12.3

13.1

14.7

47.9%

67.5

3 (12 pps)

10.5

11

12.1

57.1%

97.5

4 (9 pps)

9.5

9.9

10.7

63.8%

127.5

5 (7 pps)

9

9.3

9.9

68.1%

157.5

G.723.1
6.4 kbps

6 (6 pps)

8.6

8.9

9.4

71.4%

187.5

3.8-4.0

G.729ab

1 (100 pps)

42

46.8

56.4

16.5%

15

3.7-4.2

6

Mean Opinion Score is very subjective and varies from one scoring episode to another depending on a variety of

things, e.g., sample size, acoustic environment, and methodology. The values presented here are for audio with no

packet loss. Some codecs fare better than others under packet-loss conditions.

7

PPS: Packet per Second.