Setting up a PBX for Israel<->US communication

[Tzafrir Cohen]

On Wed, Feb 11, 2009 at 10:21:20PM +1100, Amos Shapira wrote:
> 2009/2/11 Gilad Ben-Yossef <gilad at codefidence.com>:
> > I and others can go on. Asterisk works. I donno about the other stuff
> 
> Thanks for the testimonial.
> 
> > (FreePBX etc.) but Asterisk is  prodction level system *If you know what you
> 
> FreePBX claims to be a nice web gui for Asterisk, that's why I asked about it.
> 
> > are doing*. Being that you are an experienced Linux user that has no issue
> > editing rc files or RTFM I believe you've already got 95% of the reasons why
> > Asterisk installation fail covered. :-)
> 
> Thanks for the reassurance. I've just ordered a vpslink Xen guest but
> the ssh latency from my home is very slow (I'm actually connected
> through a pretty good ISP). I'll try it from work tomorrow.
> 
> Is 200ms ping time too much for SIP, or is it irrelevant.

Besides the latency, another factor to consider is the jitter:

$ ping -c 10 kernel.org
PING kernel.org (204.152.191.37) 56(84) bytes of data.
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=1 ttl=52 time=232 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=2 ttl=52 time=232 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=3 ttl=52 time=233 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=4 ttl=52 time=233 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=5 ttl=52 time=233 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=6 ttl=52 time=232 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=7 ttl=52 time=233 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=8 ttl=52 time=233 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=9 ttl=52 time=232 ms
64 bytes from pub2.kernel.org (204.152.191.37): icmp_seq=10 ttl=52 time=232 ms

--- kernel.org ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 9038ms
rtt min/avg/max/mdev = 232.102/233.035/233.960/0.773 ms

As you can see, I have a very predictable latency. This generally means
packets will arrive on time.


Here's a less optimal example:

$ ping -c 10 lxer.linux.no
ping: unknown host lxer.linux.no
tzafrir at sweetmorn:~$ ping -c 10 lxr.linux.no
PING lxr.linpro.no (87.238.46.5) 56(84) bytes of data.
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=1 ttl=45 time=235 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=2 ttl=45 time=203 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=3 ttl=45 time=211 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=4 ttl=45 time=210 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=5 ttl=45 time=205 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=6 ttl=45 time=209 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=7 ttl=45 time=208 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=8 ttl=45 time=207 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=9 ttl=45 time=200 ms
64 bytes from lxr.linpro.no (87.238.46.5): icmp_seq=10 ttl=45 time=242 ms

--- lxr.linpro.no ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 9038ms
rtt min/avg/max/mdev = 200.634/213.566/242.968/13.399 ms

-- 
Tzafrir Cohen         | tzafrir at jabber.org | VIM is
http://tzafrir.org.il |                    | a Mutt's
tzafrir at cohens.org.il |                    |  best
ICQ# 16849754         |                    | friend