Toshiba CTX28 用户手册
IP Telephony and QSIG Over IP
Private Networking Over Internet Protocol
Strata CTX I&M 06/04
9-41
IP T
e
le
pho
n
y
and Q
S
IG
Ov
er
I
er
I
P
Strata Net QSIG Over IP and IPT Bandwidth Requirements
The bandwidth requirements for Strata Net QSIG over IP is the same as those for IP telephones.
Refer to
Refer to
to estimate the quality of service (Excellent, Good, Fair, and Poor)
provided by CTX IP QSIG channels depending heavily on the LAN parameters.
When sharing voice and data on the same network segment, the data will cause some jitter in voice
communications, especially on slower segments.
communications, especially on slower segments.
shows calculations of the amount of
jitter assuming a worst case data packet size of 1500 bytes (Maximum Transmission Unit (MTU) =
1500) based on a segment’s bandwidth. This also requires that the routers connecting the segment
through the WAN support Diffserv.
1500) based on a segment’s bandwidth. This also requires that the routers connecting the segment
through the WAN support Diffserv.
Note
A router that doesn’t support Diffserv may stack multiple data packets together increasing
the jitter perhaps indefinately. And the voice quality will be indeterminate.
the jitter perhaps indefinately. And the voice quality will be indeterminate.
Class definition categories are shown in
independent of the amount of voice traffic.
Table 9-11
QSIG over IP Jitter on Mixed Voice and Data WAN
No. of
B-Channels
of WAN
Bandwidth
(kbps)
Time to
transmit max.
MTU (ms)
Expected
Jitter (ms)
Class
2
128
93.75
100
Poor
4
256
46.88
50
Fair
6
384
23.44
30
Fair
8
512
15.63
20
Good
24
1536
1.00
1
Excellent
Table 9-12
QSIG over IPClass Definitions
Class
Delay (ms)
Jitter (ms)
Excellent
< 20
< 10
Good
< 50
< 20
Fair
< 100
< 50
Poor
< 200
< 100
Table 9-13
QSIG over IP Bandwidth
Required for Call Setup
Required for Call Setup
Traffic Rate
(BHCA
1
)
1. BHC = Busy Hour Call Attempts
Required
Bandwidth
1000
6
2000
12
4000
23
6000
36