Odd - do the phones just randomly egress from different IPs in the pool if you don't? Is this perhaps a too-long registration interval issue? Short registration timers seem to deal with keeping the state table appeased on most firewalls. Any chance the NAT device has some god-forsaken ALG agent installed that's trying to proxy the SIP traffic?
(Yes, I hate ALGs. They are evil.) Nathan > -----Original Message----- > From: Owen DeLong [mailto:o...@delong.com] > Sent: Monday, February 28, 2011 11:26 AM > To: Bret Palsson > Cc: nanog@nanog.org > Subject: Re: What vexes VoIP users? > > Another vexation for VOIP in the SMB environment is that it rarely works > particularly well (if at all) in light of a multiple-external-address NAT > pool. > > You simply have to map all of your VOIP phones in such a way that they > consistently get the same external IP every time or shit breaks badly. > > Owen > > On Feb 28, 2011, at 11:11 AM, Bret Palsson wrote: > > > Since our company is a VoIP company, I will chime in to this topic. > > > > Let's start off with the definitions so everyone is on the same page: > > > > vex |veks| > > verb [ trans. ] > > make (someone) feel annoyed, frustrated, or worried, esp. with trivial > > matters : the memory of the conversation still vexed him | [as adj. ] > > ( vexing)the most vexing questions for policymakers.] > > > > Alright, now that that's out of the way... > > > > I am only referring to small medium business and some enterprise > > (Those are all our customers, we do not do residential) > > - Seemingly complex. > > - Worried about the "What if the internet goes down" scenario. > > - Call quality. > > - Price > > - Location > > - Outages > > > > Responses: > > - Seemingly complex... Very true. Most VoIP companies, both hosted and > on premises are difficult/time consuming to setup and make work they way > you want it. > > - What if the internet goes down. This one is a challenge. POTS actually > have issues too, but when analog phone service goes down, there is no light > on the phone indicating that the phones are not working so many customers > perceive there is a problem. With the FCC mandating all POTS move to a VoIP > backend (which for long hauls, is mostly already true) POTS will experience > the same downtime as the internet. > > However as we all know, the internet is built to tolerate outages. > > For most people they don't understand how the internet actually works. > > - Call quality... If a VoIP company pays for good bandwidth and maintains > good relationships with peers, the only concern is the last-mile(From the CO > to location). Now there is much more that plays in quality, ie. codec > selection, > voice buffer, locality to the pbx. > > - Price... Believe it or not people are worried about paying less for better > service. Who would have thought? > > - Location... Location is super important both in the last mile and PBX. > > - Last mile: > > In older locations the copper in the ground is aged, if you > can't get fiber and your stuck using T1, lines, then hopefully you are in a > location that keeps the copper in the ground properly maintained. If you are > in older locations, which one of our offices are, there are remedies, you can > contact your bandwidth provider and have them do a head to head test using > a BERD (bit error rate detector) and they can find the problem. But that's a > whole other topic. > > > > -PBX: > > Some people believe that on premise is the best location for > a PBX, this may or may not be true. I happen to believe that keeping it off > premise is the way to go. You get up-time, redundancy, locality, and mobility. > You just plug in your phone and your phone is up and running. Move offices.. > got bandwidth? Your good to go. No equipment to worry about, say a power > outage happens, your voicemail still works people call in and are in call > queues and have no clue you are down. Feels more like POTS with an > enterprise backend. > > > > -Outages: If the internet does fail, most providers offer WAN survivability. > The customer plugs in phone lines into the router and if the internet goes > down, they can make emergency calls or calls to the world limited by the > number of lines the router can accept and are plugged in of course. Now in all > our experience going on 7 years now, 90% of the time WAN outages happen, > guess what also dies, the POTS! Who would have thought that when cables > get cut, that the phone lines were also part of the cables? > > > > There you go, some common worries, with some answers to hopefully > sooth the vexed VoIP user. > > > > Bret Palsson > > Sr. Network & Systems Administrator > > www.getjive.com > > > > > > On Feb 28, 2011, at 11:37 AM, valdis.kletni...@vt.edu wrote: > > > >> On Mon, 28 Feb 2011 13:29:08 EST, Bret Clark said: > >>> On 02/28/2011 01:17 PM, Leigh Porter wrote: > >>>> VoIP at the last mile is just too niche at the moment. It's for people on > this list, not my mother. > >> > >>> Baloney...if that was the case, then all these ILEC's wouldn't be > >>> whining about POT's lines decreasing exponentially year over year! > >> > >> I do believe that the ILEC's are mostly losing POTS lines to cell > >> phones, not to VoIP. I myself have a cell phone but no POTS service > >> at my home address. On the other hand, I *am* seeing a metric ton of > >> Vonage and Magic Jack ads on TV these days - if VoIP is "too niche", how > are those two making any money? > >> > > > > > >
