Forums

VOIP bandwidth conflicts

Started by John Larkin October 26, 2017

We are planning the networking for our new place. It will be all GHz
CAT6, with a couple of 48-port switches. We'll be going VOIP for the
telephones, which means that each rented phone just plugs into the
nearest ethernet switch.

Our IP consultants want a separate network and separate switches for
the phones, their concern being that data traffic could make the
phones strutter. We don't have gigantic data traffic, and ethernet is
supposed to manage traffic anyhow, so I think the concern is
overblown. 

If we buy the expensive smart/managed switches, which they also want
us to do, we can also throttle various ports if we do have problems.

I think the consultants are a bit over-the-top. They would probably
install the gear and wiring and manage the smart switches, so their
incentives are not my incentives.

They also don't like microwave internet access, but a MonkeyBrains
dish on the roof would be a heap cheaper than digging up the sidewalk
for fiber or whatever. The microwave hop would be two blocks with a
173 dB link budget.

Any experience with running data and voice over the same network? Any
advice?



-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics 

On Thu, 26 Oct 2017 08:53:59 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

> > >We are planning the networking for our new place. It will be all GHz >CAT6, with a couple of 48-port switches. We'll be going VOIP for the >telephones, which means that each rented phone just plugs into the >nearest ethernet switch. > >Our IP consultants want a separate network and separate switches for >the phones, their concern being that data traffic could make the >phones strutter. We don't have gigantic data traffic, and ethernet is >supposed to manage traffic anyhow, so I think the concern is >overblown. > >If we buy the expensive smart/managed switches, which they also want >us to do, we can also throttle various ports if we do have problems. > >I think the consultants are a bit over-the-top. They would probably >install the gear and wiring and manage the smart switches, so their >incentives are not my incentives. > >They also don't like microwave internet access, but a MonkeyBrains >dish on the roof would be a heap cheaper than digging up the sidewalk >for fiber or whatever. The microwave hop would be two blocks with a >173 dB link budget. > >Any experience with running data and voice over the same network? Any >advice?
Depends on the codec used. See <https://www.voip-info.org/wiki/view/Asterisk+bandwidth+iax2> We have 2 VOIP remote phones running over RV042's. The RV042 is also the gateway for the shop. 100/30 cable plan. For these two phones with both callers yakking it should be 160kpbs. Other than client side problems I don't see any problems, but the port is prioritized so the packets get thru. How many lines? the managed switches would be the way to go. Networks performance is much better with that type of hardware. Cheers
John Larkin wrote:
> Any experience with running data and voice over the same network? Any > advice?
It's been data and voice on the same network every place I've seen except for congressional offices. They split it for security.
On 2017-10-26 09:35, Martin Riddle wrote:
> On Thu, 26 Oct 2017 08:53:59 -0700, John Larkin > <jjlarkin@highlandtechnology.com> wrote: > >> >> >> We are planning the networking for our new place. It will be all GHz >> CAT6, with a couple of 48-port switches. We'll be going VOIP for the >> telephones, which means that each rented phone just plugs into the >> nearest ethernet switch. >> >> Our IP consultants want a separate network and separate switches for >> the phones, their concern being that data traffic could make the >> phones strutter. We don't have gigantic data traffic, and ethernet is >> supposed to manage traffic anyhow, so I think the concern is >> overblown. >> >> If we buy the expensive smart/managed switches, which they also want >> us to do, we can also throttle various ports if we do have problems. >> >> I think the consultants are a bit over-the-top. They would probably >> install the gear and wiring and manage the smart switches, so their >> incentives are not my incentives. >> >> They also don't like microwave internet access, but a MonkeyBrains >> dish on the roof would be a heap cheaper than digging up the sidewalk >> for fiber or whatever. The microwave hop would be two blocks with a >> 173 dB link budget. >>
That microwave hop should work provided the underlying infrastructure has enough bandwidth even when lots of customers stream some ballgame. The path should also be unobstructable. All it takes is a glitter-colored sales event ballon in the air and it's all over. Though silence on the network can have a soothing effect on modern mankind. When the Internet went down for four days a while ago it wasn't all bad. No more looking up web cheat sheets for calcs, had to use a book.
>> Any experience with running data and voice over the same network? Any >> advice? > > Depends on the codec used. See > <https://www.voip-info.org/wiki/view/Asterisk+bandwidth+iax2> > > We have 2 VOIP remote phones running over RV042's. The RV042 is also > the gateway for the shop. 100/30 cable plan. For these two phones with > both callers yakking it should be 160kpbs. Other than client side > problems I don't see any problems, but the port is prioritized so the > packets get thru. > > How many lines? the managed switches would be the way to go. Networks > performance is much better with that type of hardware. >
I have no personal experience but clients who switched to VoIP without a 2nd network. "Please say again?" ... "The pler section kage" ... "Say what?" ... "Oh, yeah, we just switched to VoIP, let me call you from my cell". -- Regards, Joerg http://www.analogconsultants.com/
On Thursday, October 26, 2017 at 11:54:06 AM UTC-4, John Larkin wrote:

> > Our IP consultants want a separate network and separate switches for > the phones, their concern being that data traffic could make the > phones stru. tter. We don't have gigantic data traffic, and ethernet is > supposed to manage traffic anyhow, so I think the concern is > overblown. > > > > They also don't like microwave internet access, but a MonkeyBrains > dish on the roof would be a heap cheaper than digging up the sidewalk > for fiber or whatever. The microwave hop would be two blocks with a > 173 dB link budget. > . > Any advice? > >
Get a quote from your IP consultants for what the consultants want , and also what you think is adequate and a quote for changing what you think is adequate to what the consultants want. If the quotes are reasonable you can start with what you think is adequate and if necessary go to what the consultants recommend. Yeah it might cost more, but could also cost less. Dan
> > -- > > John Larkin Highland Technology, Inc > > lunatic fringe electronics
John Larkin <jjlarkin@highlandtechnology.com> wrote:
> > > We are planning the networking for our new place. It will be all GHz > CAT6, with a couple of 48-port switches. We'll be going VOIP for the > telephones, which means that each rented phone just plugs into the > nearest ethernet switch. > > Our IP consultants want a separate network and separate switches for > the phones, their concern being that data traffic could make the > phones strutter. We don't have gigantic data traffic, and ethernet is > supposed to manage traffic anyhow, so I think the concern is > overblown. > > If we buy the expensive smart/managed switches, which they also want > us to do, we can also throttle various ports if we do have problems.
Normally VoIP is implemented on a separate VLAN on the switches (there are protocols to have the phones jump to the correct VLAN automatically so it causes no setup nightmare) and this VLAN is tagged with a higher priority than the base DATA VLAN. Then there is no issue when the DATA network is saturated, as the voice traffic goes first. This is possible with all but the most basic switches, don't let them claim you need expensive Cisco switches for it.
On 26 Oct 2017 19:23:43 GMT, Rob <nomail@example.com> wrote:

>John Larkin <jjlarkin@highlandtechnology.com> wrote: >> >> >> We are planning the networking for our new place. It will be all GHz >> CAT6, with a couple of 48-port switches. We'll be going VOIP for the >> telephones, which means that each rented phone just plugs into the >> nearest ethernet switch. >> >> Our IP consultants want a separate network and separate switches for >> the phones, their concern being that data traffic could make the >> phones strutter. We don't have gigantic data traffic, and ethernet is >> supposed to manage traffic anyhow, so I think the concern is >> overblown. >> >> If we buy the expensive smart/managed switches, which they also want >> us to do, we can also throttle various ports if we do have problems. > >Normally VoIP is implemented on a separate VLAN on the switches >(there are protocols to have the phones jump to the correct VLAN >automatically so it causes no setup nightmare) and this VLAN is >tagged with a higher priority than the base DATA VLAN. Then there >is no issue when the DATA network is saturated, as the voice traffic >goes first. > >This is possible with all but the most basic switches, don't let >them claim you need expensive Cisco switches for it.
This isn't bad, https://www.amazon.com/dp/B00JJ4XNHK/ref=psdc_281414_t3_B00BHZJMB0 52 ports, gbit, poe, managed, under $1K. Two of those would cover the whole building forever. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
"John Larkin" <jjlarkin@highland_snip_technology.com> wrote in message 
news:m6e4vc1usamtqfd5en8kjhvajvo8q19f5t@4ax.com...
> On 26 Oct 2017 19:23:43 GMT, Rob <nomail@example.com> wrote: > >>John Larkin <jjlarkin@highlandtechnology.com> wrote: >>> >>> >>> We are planning the networking for our new place. It will be all GHz >>> CAT6, with a couple of 48-port switches. We'll be going VOIP for the >>> telephones, which means that each rented phone just plugs into the >>> nearest ethernet switch. >>> >>> Our IP consultants want a separate network and separate switches for >>> the phones, their concern being that data traffic could make the >>> phones strutter. We don't have gigantic data traffic, and ethernet is >>> supposed to manage traffic anyhow, so I think the concern is >>> overblown. >>> >>> If we buy the expensive smart/managed switches, which they also want >>> us to do, we can also throttle various ports if we do have problems. >> >>Normally VoIP is implemented on a separate VLAN on the switches >>(there are protocols to have the phones jump to the correct VLAN >>automatically so it causes no setup nightmare) and this VLAN is >>tagged with a higher priority than the base DATA VLAN. Then there >>is no issue when the DATA network is saturated, as the voice traffic >>goes first. >> >>This is possible with all but the most basic switches, don't let >>them claim you need expensive Cisco switches for it. > > This isn't bad, > > https://www.amazon.com/dp/B00JJ4XNHK/ref=psdc_281414_t3_B00BHZJMB0 > > 52 ports, gbit, poe, managed, under $1K. Two of those would cover the > whole building forever. > > > > > > -- >
Used Cisco Catalyst POE switches are dirt cheap. Split up your phones on different switches so if one fails, you still can call for help. Give the voice and video devices a high priority with the tagging. The priority is set in the router using QoS settings. Put all the phones on one VLan, the same with video. Consider having a separate management VLan. For the microwave, you might consider using the 60 GHz unlicensed band where you can get Gbit and higher rates. That band is also range limited because of the O2 absorption band. It is reliable to about 1/2 mile. You could also do a backup path at 24 GHz but somewhat limited bandwidth (500 to 700 Mbps or less if you want top use small dishes). Have fun. Check with your ISP on what VOIP considerations they might have. Regards
On Thu, 26 Oct 2017 08:53:59 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>We are planning the networking for our new place. It will be all GHz >CAT6,
Good. I suggest you consider fiber for any high traffic internal backbones, such was the machine that's doing workstation (image) backups.
>with a couple of 48-port switches.
Duz a "couple" mean two? A few problems here. Make sure they're "managed" switches, which is IT talk for supports SNMP. Troubleshooting switch problems without traffic and error data via SNMP is a PITA. 48 ports is a good number depending on your undisclosed number of client machines, printers, gizmos, gadgets, test equipment, and such that require ethernet ports. I usually recommend at least twice the number of ports per switch (and per room) as there are devices that can be identified when the system is planned. I'm usually close. Ethernet switches with lots of ports is the ultimate single point of failure. Everything goes through the switch. If the switch goes up in smog, your entire network and everything plugged into it are dead in the water. From my warped perspective, that means you buy the best, monitor performance, and have spares on hand. Be prepared to abandon blown ports. For Cisco, have spare replacement power supplies handy. Unfortunately, my customers are cheap, so I have a few old 10/100 switches with 8 to 48 ports handy which allows my to throw something together until the big switch can be replaced. The problem with this is that if you setup a VLAN (virtual LAN) replacing the big switch with lesser devices isn't going to work well. That's one reason for SDN (Software Defined Networks): <https://en.wikipedia.org/wiki/Software-defined_networking> You're not big enough to need or want such a thing (and the IT staff that comes with it) but you should be aware of the technology.
>We'll be going VOIP for the >telephones, which means that each rented phone just plugs into the >nearest ethernet switch.
Make sure your ethernet switch provides PoE (Power over Ethernet) or you will have a tangle of AC adapters everywhere. Well, you'll probably have such a tangle anyway as they're hard to avoid, but PoE will eliminate at least one wall wart per desk. Also, do the math an add up the power consumption of the phones and make sure that the total PoE power provide by the switch is adequate. While most switches have PoE on all ports, they may not have enough power to drive all the ports at the same time. Also, some switches are rated for only powering half the ports.
>Our IP consultants want a separate network and separate switches for >the phones, their concern being that data traffic could make the >phones strutter.
Not always. Add up your VoIP network traffic and you'll find that it's trivial compared to the available gigabit bandwidth. What causes the VoIP garble are applications that are capable of sucking ALL of that available bandwidth, leaving nothing for VoIP. If you are hearing garble, you're LAN is dropping UDP VoIP packets probably due to congestion. You have a few options here for managing your bandwidth: 1. Separate LAN switches and separate wiring for each network. That doubles your wiring in the walls, doubles the network cost, and does nothing to protect the network from the real bandwidth hogs (video and backups). Are you also going to install a separate LAN for video and backups? 2. VLAN (Virtual local area network). This allows you to break your network apart into several segments, and assign each ethernet port to one of the networks. In simulates having multiple switches. To avoid having to run two cables to each desk (one for data and one for VoIP), there's 802.1Q packet tagging, which designates the target VLAN. 3. Brouter (bridge-router). Switches work on the MAC address layer (layer 2). Bridges add the IP layer (layer 3). Layer 3 switching allows you to introduce QoS (quality of service). QoS is simply a filtering service that reserves some bandwidth for time critical services at the expense of less time critical services. It's quite common in home routers to deal with SIP (VoIP) phones and limited internet bandwidth. You won't like the prices on the brouters. <https://en.wikipedia.org/wiki/Bridge_router> You're probably going to have the biggest problem with traffic contention in your internet router. You may have gigabit bandwidth on your LAN, but you probably don't have anywhere near that much on your internet connection. Make sure you enable and configure QoS to give preferential treatment to SIP (VoIP) packets. What's nice about ethernet is that traffic between two ports does NOT affect traffic between two other ports. That means you can run gigabit high bandwidth backups between two ports, and talk with VoIP between two other ports without the high bandwidth traffic affecting the VoIP in any way. Well, almost any way. The switch has a maximum internal backplane bandwidth which cannot be exceeded. For high end Cisco switches, it's in tens of gigabits/sec or more. For low end cheap gigabit switches, it can be as low as 2 gigabits/sec. The backbone bandwidth is also where having two or more ethernet switches. If the switches are sitting on top of each other, there are two expansion ports and interconnecting cable for expanding a switch without any loss of bandwidth. However, if the two switches are located in different parts of the building and connected with a single CAT6 cable, traffic between the two switches is limited to 1 or 2 Gbit/sec. In effect, this reduces the 10+ gigabit/sec backplane bandwidth to 1 or 2 gigabits/sec (unless you get switches with 10G fiber ethernet ports).
>We don't have gigantic data traffic, and ethernet is >supposed to manage traffic anyhow, so I think the concern is >overblown.
I've done quite well helping customers who made similar assumptions get their VoIP running. I don't believe anyone's data traffic numbers until I've sniffed and measured their traffic. You're probably right about the average traffic, but I don't think you're considering your peak traffic. Gigabit networks offer considerably faster response times. When I upgrade networks to gigabit (usually by just replacing the 10/100 switches with gigabit and leaving the CAT5e alone), everything seems to go faster. The programs aren't running much faster, but the response time to anything requiring server access is much faster. Individually, it's probably only about 100 msec per keystroke or mouse click, but multiplied by the number of keystrokes a person does on a typical day, the effect is substantial. Ethernet (Layer 2) doesn't really manage traffic. It uses a CSMA/CD algorithm to deal with collisions and juggles packets sizes. Retransmissions and error control are handled by TCP/IP on Layer 3. The CSMA/CD algorithm breaks down when the network segment is near maximum capacity, which is quite common with todays bloated software and bursty traffic application. You can count on ethernet to do its job at low or moderate traffic levels, but not so much at high levels.
>If we buy the expensive smart/managed switches, which they also want >us to do, we can also throttle various ports if we do have problems.
Sure. A VoIP phone doesn't require any more than 10 mbit/sec port. However, once that packet gets into the switch, it's competing with high traffic programs for access to a server or router. Unless the switch has some means of prioritization, there is going to be some contention. To be fair, you're probably ok with todays applications. I'm not so sure about tomorrows apps.
>I think the consultants are a bit over-the-top. They would probably >install the gear and wiring and manage the smart switches, so their >incentives are not my incentives.
Yep, that's about it. Your IT people are covering their posterior by overdesigning your system. I would do the same. I don't like working right on the edge of a capacity limit. Running out of ports, failure to disclose badly behaving applications, and devices that nobody mentioned are common. Never mind rogue access points, malware, and spam servers. I try to plan for at least 1 year's worth of capacity expansion. Planning only for tomorrow is a bit tight for me.
>They also don't like microwave internet access, but a MonkeyBrains >dish on the roof would be a heap cheaper than digging up the sidewalk >for fiber or whatever. The microwave hop would be two blocks with a >173 dB link budget.
I would be more interested in the fade margin. Gigabit wireless ethernet is quite common these daze. I've only done one 60 Ghz link. I had a hell of time getting the dishes aligned and then keeping them aligned after I discovered that rooftop shelter moved when the elevator reached the top floor. Oxygen absorption was not a problem and actually advantage in that it attenuated interference from other rooftop 60GHz links. Of course, the chose line of sight pointed almost directly at another 60GHz antenna. Heavy rain was a problem, but worked ok in light rain or fog. There were some outages, which I like to attribute to birds, but I'm not sure. Most of the downtime was caused by people working on the rooftops, such as HVAC and cellular antenna.
>Any experience with running data and voice over the same network? Any >advice?
Sure. It works as long as you can prevent applications from saturating backplanes, backbones, and network segments. Use G.711 (90kbits/sec0 uncompressed codec for intelligibility. There are VoIP bandwidth calculators available: <https://www.bandcalc.com> Calculate your worst case bandwidth consumption assuming all the phones are in use simultaneously. You can simulate how it would work with your present ISP and connection at various VoIP test sites: <http://voiptest.8x8.com> Watch out for jitter and packet loss. Drivel: Every time I move, it's either the hottest day of the year, or it's raining. Good luck. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Thu, 26 Oct 2017 08:53:59 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

> > >We are planning the networking for our new place. It will be all GHz >CAT6, with a couple of 48-port switches. We'll be going VOIP for the >telephones, which means that each rented phone just plugs into the >nearest ethernet switch. > >Our IP consultants want a separate network and separate switches for >the phones, their concern being that data traffic could make the >phones strutter. We don't have gigantic data traffic, and ethernet is >supposed to manage traffic anyhow, so I think the concern is >overblown. > >If we buy the expensive smart/managed switches, which they also want >us to do, we can also throttle various ports if we do have problems. > >I think the consultants are a bit over-the-top. They would probably >install the gear and wiring and manage the smart switches, so their >incentives are not my incentives. > >They also don't like microwave internet access, but a MonkeyBrains >dish on the roof would be a heap cheaper than digging up the sidewalk >for fiber or whatever. The microwave hop would be two blocks with a >173 dB link budget. > >Any experience with running data and voice over the same network? Any >advice?
Ours are run over the same networks, sometimes computers being plugged into the phone's aux port, and everything works OK. I hate the phone system but the phone itself works fine. They're nice because they'll work anywhere on our network, even across town or in another state. ...not that we carry our phones with us.