[asterisk-users] Help with concurrent VoIP calls

[Joe Greco]

> By "fast" I mean the best Business DSL Bellsouth has to offer: "Up to
> 6.0 Mbps downstream - Up to 512 Kbps upstream"

That almost sounds like an invitation to check out what business service
your cableco offers.

One thing to be aware of with DSL and cable modems is that there can be
various ill effects as your line gets closer to its rated capacity; do
not expect that you'll get a reliable 512Kbps upstream.  VoIP is sensitive
to loss, latency, and jitter.  You may be able, for example, to only get
384Kbps reliably out of the link (before packet loss/jitter/etc wreck its
suitability for VoIP).  That's a good time to look seriously at a gateway
package like pfSense that can prioritize certain classes of traffic while
also limiting overall bandwidth.

As an example, we noticed on the local business cable offering (2Mbps up)

Shaped 	PL	min	avg	max	stddev
2.2M	3	6.4	251	557	176
2.1M	1	7.8	350	584	134
2.0M	3	6.4	271	535	132
1.9M	1	7	254	527	131
1.8M	0	6	79	339	90
1.75M	0	5.9	14	92	11
1.7M	0	5.4	13	77	10
1.65M	0	4.9	11	69	7
1.6M	0	5.4	13	55	9
1.5M	0	5.3	11	59	7
1.4M	0	5	11	57	7
1.3M	0	4.9	11	54	6
1.2M	0	4.9	11	52	7
1.1M	0	4.8	14	53	11

The max starts trending up after 1.6M (helps to graph it) and pretty much
everything goes to hell after 1.75M.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.