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wayland_smithy 12/4/2012 | 9:18:31 PM
re: No VOIP for Panama replying to rfc1633:

Some good points here, and I agree with some of them. Let me come back on a couple :

> Here, I think QoS and blocking are two different things:

Yes, agree completely. I guess I was making a point that, on TDM circuits, let's not assume that every call originated gets through at 100% quality. Some calls are blocked, other voice calls can sound like your head is buried in a tinbucket if, for example, compression/cancellors are used. Also, bandwidth is "nailed up" for TDM for the life of that call - inefficient but dedicated.
With IP, QOS is a different proposition. What it effectivley allows you to do is to regulate the quality of the service versus bandwidth across a network: a completely different way of addressing the problem. You could, therefore, go for a high QOS where you assign higher priority (~ bandwidth) to voice at the expense of other traffic types. QoS could essentially be used to trade off number of calls/bandwidth usage versus quality (that comment will get some posts !!)so you could argue you can engineer a network to use bandwidth more effectively at the expense of "perceived voice quality". IP makes the deployment a little more flexible in its nature.

>>>But for mobility, it's not that simple as you said. If you roaming freely, without any extra pay, that means there must sb else pay for that. This must be SP. If so, why SP stupidly provide such service ?

Again, a fair point. With IP Telephony, however, the assumption is that many Enterprises already have their own IP Data Network, and are carrying the call to the endpoint as far as possible over this IP network. In this case, the SP will never see the traffic. If it breaks out the voice to the PSTN, the SP will see a call originated on thier network as close as possible to the destination phone: this means reduced revenues anyway. This is not dissimilar to doing this on a private voice TDM network using Least Cost routing - keeping the voice call on your own network as far as possible before breaking out over the PSTN to minmise call payments to the SP.

However, with IPT the argued advantage is that you can carry telephony over the data network, as opposed to having either 2 separate networks (the voice one of which is inefficiently used since the bandwidth is only utilised for the duration of the call) or having a voice/SDH/SONET network over which 90% of the traffic is typically data & therefore also inefficiently handled. There is also the cost of managing the network - when I worked at Nortel, one of the biggest problems we saw for carriers offering managed services (Centrex) was the cost & time of Add/move/changes on the networks requested by the end users: if this "mobility" exists, costs of managing the network decreases a lot since you won't be moving phones or phone numbers around manually.

For the SP revenue side, you are correct: SPs will now have to start moving away from offering raw bandwidth circuits & voice minutes to moving up the service revenue ladder. So, to do that, they will need to minimise infrastructure management costs & start looking at service revenue generation over that infrastructure, whilst reducing the cost of managing the network.

This has happened to an extent in the public voiceinfrastructure - whereas 10 years ago, your 56K/64K phone line to your house delivered only dialtone (and in the US your SP didn't even get revenue for local calls),but now, on that same piece of copper, SPs can offer voicemail, call forward, do not disturb, etc. and such features generate additional revenue along that same piece of cable - this moves them up the value chain and increases revenue for the same chunk of bandwidth.
If the same argument now applies, for example, to delivering an Ethernet pipe to the home/business, IP Telephony, VideoIP and Data/Internet services all could generate additional revenue for that same piece of copper/fibre (this isthe trend you are seeing in Europe now with newer SPs or CLECs). It also allows service differentiation to other competitors, whereas currently differentiation tends to be on a price per circuit basis for a limited number of services., and this leads to commoditisation.

So, what does this mean ? VoIP should indeed be cheaper to deploy over time for Enterprises initially, and then SPs (one IP/MPLS/ATM network for voice & data, reducing management & maintenance staff costs & getting rid of inefficient voice networks carrying 90% data) with additional services enabled on the same infrastructure to deploy revenue-generating services....well, that is the theory anyway. Over time, if it does take off, Enterprises will less likely be asking for an SDH/SONET tail circuit to the premise (since they won't have a PBX & it doesn't makesense to carry IP over SONET: and the price of a SONET interface for their router is 2-5 the cost of an Ethernet interface) and more likely to ask for a "big fat IP/Ethernet pipe with VPN/guaranteed QOS/VPLAN" type functions. They are also possibly more likely to take provisioned/managed services from the SP since "mobility" makes it more cost effective for both parties to offer/taker these services.

Where I;m not yet convinced, however,is the argument where you are simply replacing a TDM 2MBcircuit interface on a PBX for a packet interface on a PBX as a "protocol converter" - the key to VoIP telephony is in the services & mobility across a very wide area network and not a PBX node/cluster.
Packet Man 12/4/2012 | 9:18:30 PM
re: No VOIP for Panama Excellent post, I wish I could put thought into word like that.

Packet Man 12/4/2012 | 9:18:30 PM
re: No VOIP for Panama Your comment:
It seems very typical that a Canadian carrier
would - true to form - buy from a Canadian
equipment provider (let's keep those loonies
flying in tight formation, eh?). Also not
unusual to have a legacy ATM core (hence the
Nortel Passport). Finally, I can't see them
ignoring the eventuality of VOIP. Seems like the
usual progression. Am I off-base?

Canadian carrier also had a bunch of Voice over packet (IP and/or ATM) Softswitches made by a company called Telica out of Mass.


I'm not sure if they are still using it or if they sent it back. But still maybe ATM today, it will be VoIPoATM tommorrow, and then VoIP only later. Where MPLS fits into this I can't comment.


sgan201 12/4/2012 | 9:18:29 PM
re: No VOIP for Panama Hi Packet Man,
You could make anything to work if you waste enough bandwidth on it..
If you have direct fibre between two phones, you can run any protocols and it will work..
Basic questions, how much bandwidth it take to deliver a phone calls??
If it is VoATM, it is X..
If it is VoIP, it is 2X due packet size..
The trunk utilization need to be less than 40% to control jitter. Hence, it is another 2.5 times..
The bottomline, it is 5X..
As a carrier, unless you get bandwidth for free..
Why are you using 5X bandwidth to deliver a phone call with lower QOS than VoATM or TDM?? It is commodity services..
For enterprise, VoIP on LAN make sense..
VoIP on WAN -> You must be kidding..
I can get more phone calls on a T1 line and better QOS with VoFR..
Packet Man 12/4/2012 | 9:18:28 PM
re: No VOIP for Panama IP overhead is less than ATM overhead, so how can you say VoIP is 2X when compared to ATM? VoIPoATM would be wastefull. G.711 VoIPoPPP is 82.4Kbps, and G.711 VoIPoATM is 106Kbps! G.729 is 26.4 / 42.4 respectivly. Toss in cRTP and the numbers become G.711 67.2K and G.729 11.2K for VoIP.

Trunk utilization needs to be less than 40% to control jitter? Says who? I did a stress test for a project and had the WAN link at 94% utilization, and that was on a 768Kbs with 30 simulteanous FTP sessions, and a couple of Citrix streams going across the same link. I had six G.711 voice calls up and all sounded perfect for the 20 minute test. I also used staff from our DMS100 toll group to provide the ears for the calls and got two thumbs up.

Mind you the FTP wasn't the fastest, but that how the customer wants it.


wayland_smithy 12/4/2012 | 9:18:28 PM
re: No VOIP for Panama dreamer101 wrote: I can get more phone calls on a T1 line and better QOS with VoFR..

...actually, you can get only 24 simultaneous phone calls only at one time on your T1 (30 if you had the sense to configure it as an E1 and use those 6 extra channels)........can anyone IP-clueful calculate what that 1.5/2MB bandwidth would get you in terms of simultaneous VoIP calls for comparable quality (this should bring some interesting answers - BobbyMax, where are you when your logic is needed ?)
Packet Man 12/4/2012 | 9:18:26 PM
re: No VOIP for Panama This math is open for discussion:

1.544Mbps / 11.2Kbps (G.729 on cRTP VoIP) = 137 calls.

1.544Mbps / 26.4 Kbps (G.729 on VoIP with no cRTP) = 58 calls.

1.544Mbps / 67.2Kbps (G.711 on VoIP with cRTP) = 22 calls.

1.544 Mbps / 82.4Kbps (G.711 on VoIP no cRTP) = 18 calls.

This is based on 0% being used for data and video.

In large scale networks VAD will increase the numbers of calls, but can make planning trickery. Also one should take away 20 to 25% of the WAN circuit (in this case 1.544Mbps) to allow for routing protocol overhead, etc. Monitor the network and them maybe bring that number down if safe to do so. A small remote office could use static routes and thus free up bandwidth to get another call or two plus some for data.

sgan201 12/4/2012 | 9:18:23 PM
re: No VOIP for Panama Hi wayland,
I meant to say that you can get more phone call with VoFR as compared to VoIP on a T1 line.
VolTrdr 12/4/2012 | 9:18:22 PM
re: No VOIP for Panama To all VoIP naysayers

I've been using residential VoIP service in my apt. for approximately four months now through Vonage, and I can
tell you I couldn't be happier with the service. I got sick of having to pay >$40/mo. for a Verizon
landline which I hardly used on top of long distance charges. Now I pay $22/mo. for all my local and long distance calls plus
I get call waiting, caller ID, call forwarding, LNP, voicemail, a call log, and can even listen to my voicemails on the Internet.

The quality of the calls is slightly less than toll quality, but to most people I talk to, the difference is indiscernible. In fact, most people are shocked
when I tell them I use IP phone service.

I'm not a telecomm person, so I can't tell you how they employ QOS (if at all), but I can tell you it works...well. The only
requirement is that you have a broadband connection with 90kpbs of upstream bandwidth and a router. Vonage supplied me
with the Cisco voice router that sits on top. Set up was a snap.

The best part is that I don't have to keep changing my phone number when I move. I've moved four times in the last five
years and changing phone service/numbers is a pain to say the least, and, even though I live in NJ, I got a Manhattan area code
for my number since that's where most of my friends/family live.

Verizon take heed because when the word gets out how well this works, it's game over for the incumbents. For all the naysayers,
just do a search on the web for "Vonage" and see if you can find a post from one disgruntled customer.

sgan201 12/4/2012 | 9:18:21 PM
re: No VOIP for Panama Hi VolTrdr,
Goto www.dslreports.com and check under VoIP forum to find a list of complains about Vonage services..
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