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mozerd
Light Will Pierce The Darkness
Premium,MVM
join:2004-04-23
Nepean, ON

1 recommendation

reply to Waffle

Re: [Windows] Help with Office Network (T1)

Your VoIP requires that you reserve 640 Kbps of bandwidth full duplex. In view that its a T1 you do have control of both ends via the Samsung UBIgate 1000 and its QoS capability. The VoIP should be on a segregated subnet dedicated to VoIP. How do I arrive at 640Kbps? each VoIP phone will require 128Kbps full duplex and I assume that your office phones will all be active at the same time. Since your T1 provides 1.544 Mbps, full duplex and you need to reserve 640Kbps for VoIP that now leaves you with 600Kbps +/- full duplex available for data traffic. For typical text based mail [lacking graphic based attachments etc], surfing without streaming video the available bandwidth should be adequate. However if Video [YouTube, Graphics, etc..] is part of the mix then your data will crawl or freeze for the number of users you have.

IMO, you would be much better off with a good broadband ISP.
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business


HELLFIRE
Premium
join:2009-11-25
kudos:18

Hey mozerd, curious where some of your numbers came from.

IIRC, VOIP typically uses either the G711 (64kbps/call) or G729 (8kbps/call) codec. Assuming the OP is using G711,
64kbps/call x 5 phones = 320kbps, then x 2 for the bidirectional; not sure where you're pulling the 128kbps from.

Also IIRC T1 is rated for 1.544Mbps, so bidirectional would be 3.088Mbps.

Either case, I agree with your assessment that if other data-intensive traffic is crossing the wire at the same time
as the calls, then OP needs to rethink the setup.

Regards


cramer
Premium
join:2007-04-10
Raleigh, NC
kudos:9

»www.cisco.com/en/US/tech/tk652/t···e2.shtml

64K is the CODEC sampling rate. There are more bits necessary to actually transmit it.



shdesigns
Powered By Infinite Improbabilty Drive
Premium
join:2000-12-01
Stone Mountain, GA
Reviews:
·EarthLink
·Comcast
·Atlantic Nexus

said by cramer:

»www.cisco.com/en/US/tech/tk652/t···e2.shtml

64K is the CODEC sampling rate. There are more bits necessary to actually transmit it.

The sampling rate of nearly all the codecs is 8K samples/sec.

As 7.11 uses 8 bits per sample, the CODEC bit rate is 64kbps.
--
Scott Henion

Embedded Systems Consultant,
SHDesigns home - DIY Welder


mozerd
Light Will Pierce The Darkness
Premium,MVM
join:2004-04-23
Nepean, ON

1 recommendation

reply to HELLFIRE

HELLFIRE, experience has no substitute -- Inexperience carries significant cost and risk. I've forgotten how many botched up installations I've had to redo based on Telco geezers believing that they follow specs to the letter and refuse to adapt to reality.

With VoIP I've leaned that 80Kbps full duplex does not cut it --- 128Kbps full duplex works very nicely each and every time especially under load of concurrent usage.
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business