I assume if they are using IP in the backbone, they aren’t doing it the same way we do VoIP on the last mile, which is very inefficient, and introduces a lot of latency.
Most voice codecs use an 8 kHz sample rate. Uncompressed G.711 uses 1 byte per sample. To match the latency of conventional POTS, you would have to send one byte per packet. What is actually done is to collect 80 samples (10 msec worth) and send those together in a packet. Even so, 80 bytes in a packet involves a lot of overhead, and you have introduced 10 msec of latency. With a compressed codec like G.729, the overhead hit due to packetizing is even greater. The other thing is, if you lose a packet, you’ve lost a lot of voice samples. Phone companies used to worry a lot more about voice quality and latency. T1 was developed for voice transmission (and pair gain), and that’s why latency specs on T1 and higher order muxes are extremely tight. Now of course cellphones have set the bar very low for voice quality, and no one sweats the difference between a MOS of 3.9 vs 4.0. It is almost comical when testing a VoIP phone to your cellphone in the same room, you can pretty much say a couple words and then wait and hear them come over the other phone, as if they went to the moon and back. I assume the 53 byte ATM cell (48 payload bytes) was chosen in part with digitized voice in mind, a tradeoff between carrying packet data and digitized voice. From: Mike Hammett Sent: Wednesday, November 25, 2015 8:53 PM To: [email protected] Subject: Re: [AFMUG] Phone System International is IP. Cable and cellular voice aren't traditional voice and if they're calling each other, don't hit the legacy PSTN. The only way to ensure your call doesn't hit IP for some of the call is to use standard POTS. ILEC tandem to CO and CO to CO, sure, but most everything else is IP or I suppose some non-legacy non-IP. Fewer and fewer are using legacy. Heck, one of my government clients is implementing AT&T SIP termination and I believe their 911 center is now IP enabled (even if nothing else is). ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -------------------------------------------------------------------------------- From: "Paul Stewart" <[email protected]> To: [email protected] Sent: Thursday, November 19, 2015 2:42:46 PM Subject: Re: [AFMUG] Phone System Most telecom/telco companies still use ATM based technology on their trunks … some of the more progressive companies (typically smaller, often SILEC’s) use as much IP as possible especially if they are providing FTTH or using DSLAM’s that are IP based. So yes, IP is getting used a lot more especially from the CO out to customer premise but from CO to CO and inter-carrier trunks are still primarily ATM From: Af [mailto:[email protected]] On Behalf Of Mike Hammett Sent: Thursday, November 19, 2015 1:07 PM To: [email protected] Subject: Re: [AFMUG] Phone System Yes, most. ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Midwest Internet Exchange http://www.midwest-ix.com -------------------------------------------------------------------------------- From: "Chuck McCown" <[email protected]> To: [email protected] Sent: Thursday, November 19, 2015 11:05:00 AM Subject: Re: [AFMUG] Phone System Hmmm, most? All my trunking is still SS7. From: Mike Hammett Sent: Wednesday, November 18, 2015 5:59 PM To: [email protected] Subject: Re: [AFMUG] Phone System Most voice traffic in the world is VoIP or a variant of VoIP. You just have bad experiences with shit systems. ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com Midwest Internet Exchange http://www.midwest-ix.com -------------------------------------------------------------------------------- From: "Jaime Solorza" <[email protected]> To: "Animal Farm" <[email protected]> Sent: Wednesday, November 18, 2015 6:36:33 PM Subject: Re: [AFMUG] Phone System Voice quality for one....it echos or audio quality is crappy. We replaced my mums TWC with fixed cellular and an ATT landline. Better all around. When I was at district with had hybrid system. The pots one had almost zero issues. The main office went to Cisco and after a few months went back to pots. At time we had 45 x 45 symmetrical link...now they have 1Gbps link.... At district our boss ran a flat network which probably contributed to much of this....not sure what they have now... On Nov 18, 2015 5:19 PM, "Faisal Imtiaz" <[email protected]> wrote: I though you were going to say.... I am old school, I don't answer the phone, I let my assistant answer it ! LOL !.. What attribute do you associate with VOIP that yo don't like ? Regards. Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] ------------------------------------------------------------------------------ From: "Jaime Solorza" <[email protected]> To: "Animal Farm" <[email protected]> Sent: Wednesday, November 18, 2015 7:15:02 PM Subject: Re: [AFMUG] Phone System Actually I am old school...I still don't like VoIP systems... Especially TWC version On Nov 18, 2015 5:04 PM, "Jaime Solorza" <[email protected]> wrote: Is that the type of phone you are using? On Nov 18, 2015 3:47 PM, "That One Guy /sarcasm" <[email protected]> wrote: Their UTM firewalls are outstanding, support impeccable, RMA process superb. Firmware updates are a PITA because of the random changes, like taking out DHCP relay from the GUI requiring CLI. Their sizing calculator is pretty spot on. They do a decent trade in for competitor replacement, just send a serial and certificate of destruction. It does suck if you dont do the maintenance contract you lose some of the UTM like webfiltering They have some 3com partnership, or they bought hem, something to that effect. Their switches are a bit big for the britches, I wasnt impressed. It can get pricey though On Wed, Nov 18, 2015 at 4:41 PM, Paul Stewart <[email protected]> wrote: Interesting …. Anyone use Fortinet gear for anything else? They keep hitting my radar for certain applications but have no real hands on with it…. They seem to make a lot of options… From: Af [mailto:[email protected]] On Behalf Of That One Guy /sarcasm Sent: Wednesday, November 18, 2015 5:34 PM To: [email protected] Subject: Re: [AFMUG] Phone System we do fortinet only You can do it without a problem its a good system as long as you realize is a voip pbx in a box, its not as configurable as some, but thats the beauty, you have a clear line of can do and cannot do Its designed to be an end user system as in you sell it to a customer and they manage it through their support contract with fortinet We have one customer who did that, he has had good success with self management, and hes a dolt at times. They bought Talkswitch so its actually a rebranded but seasoned system The virtual pbx is more scalable, but without conversion hardware it doesnt do pots On Mon, Nov 16, 2015 at 3:56 PM, Matt <[email protected]> wrote: We are looking at upgrading our phone system. Looking at Fortinet. We have two locations now with separate phone numbers. Wanting to link the systems over Internet so we can help each other out when one location or other has too many lines ringing. What is everyone else using for a phone system and how do they like it? -- If you only see yourself as part of the team but you don't see your team as part of yourself you have already failed as part of the team. -- If you only see yourself as part of the team but you don't see your team as part of yourself you have already failed as part of the team.
