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VOIP question

L

liveordie

Senior member
Hi

i have a question about our current setup and future expansion to include VOIP system. We have about 40 PCs in the office all running connected through 2 unmanaged CISCO switches (SR224 and SR224G) with Sonicwall TZ190W in front of them.

Since we want to add VOIP phones to every station would it be better to invest in managed switch in order to QoS (possibly PoE) and create separate VLANS for PCs and Phones on the LAN level? It's still going to be one wire to every station with the phone splitting it in two for desktops. Or should we just see how it works with the current setup and upgrade if the quality is not what we want.

Thanks in advance for any input.
 
It really depends. Without knowing the specifics I would say to always do it the right way which would be end to end QOS and POE with separate voice and data VLANS.

If you have the money do it the right way but if you have more time than money you might be able to get away with what you have.
 
With the sensitive nature of VOIP I strongly recommend starting with a good managed switch with a properly configured QOS policy. It has been my experience that it is easier to get approval to replace your switches at the beginning, when implementing a new phone system, and much more difficult to get them approved later. Any good VOIP phone system consultant will tell you that VLAN is required, not optional. This is what my company tells every Manager/Executive/Owner we propose a phone system to. We know it is not technically true, you can do it without VLANS, but it saves a lot of trouble and headache later.
 
For 40 phones, I would definitely, absolutely, almost require you to purchase PoE switches, at the very least. Voice VLANs are great, and can give lots of flexibility especially if the phone system is not maintained inhouse, but they are definitely not required.

My recommendation, of course, would be some managed PoE switches. Used, if you must. Some used Cisco 3550 PoE switches on Ebay wont set you back that much, and they work great.

If your VoIP system is hosted, you'll need a new router, too. Your SonicWall won't work, unless they've upgraded their software to allow you to turn off their worthless SIP ALG.
 
Also, 40 phones on a hosted system is a LOT of phones. Be wary. If your Internet connection isn't very beefy, you will have call quality problems. I typically recommend no more than 20 phones per site for my hosted PBX customers, and that depends on the type of Internet they have.

A used Cisco 3550 48pt PoE is about the only thing you're going to find for ~$300. You'll also need to make sure that your SonicWall is capable of doing an 802.1q trunk and is VLAN aware...although you could get around that with a layer 3 switch.

I would see if the vendor will send you a couple of phones prior to inking the deal to demo them with your SonicWall. My experiences with SonicWalls and VoIP have not been pleasant, and it'd leave you in a rough spot if it decided not to work after you've already signed the deal or rolled your phone numbers. What you want to look for is the ability to call one phone from another. If that doesn't work, it means the SonicWall is playing with the SIP packets, and even though the option exists to turn off the ALG, it's been my experience (albeit with older versions) that it doesn't actually turn the feature off. Definitely have a Plan B. Juniper SRX100B would be my recommended Plan B.
 
we have cable 15mpbs up and 5 down and getting some decent DSL as backup internet and POTS line in case the VOIP goes out. it's 64kbps per call so we are probably in OK spot as far as bandwidth goes and i don't expect more than 20 people on the phone at the same time. sonicwall supports 802.1q trunk and VLAN when i checked its specs but thanks on the router suggestion, just have to see if the sonicwall works, otherwise we'll look into SRX100B or perhaps pfSense box (would that be better?). yeah i have some concerns about the quality and reliability and maybe in the future we will host on premise pbx just to off load the in network calls from the internet bandwidth. thanks again for the all the info.
 
my first choice was onSIP.com, second VOIP.ms with premium addon, and then i got in touch with local VOIP reseller (start up) who gave me good pricing, if it doesn't work out with him i may look into the initial options. which ones are you using for your customers or are the ones you would recommend for larger organization?
 
I use my own. I started a hosted PBX provider. My current customers are on Asterisk, each on their own vSphere virtual machine. It's easy to set up and works wonderfully, but it's a little resource intensive, so I'm in the middle of writing my own multi-tenant setup. That'll take a bit of time, and the featureset will be the same, but it'll open up the option for me to be able to whitelabel it out for resellers.

I do my own origination and termination.
 
drebo said:
For 40 phones, I would definitely, absolutely, almost require you to purchase PoE switches, at the very least. Voice VLANs are great, and can give lots of flexibility especially if the phone system is not maintained inhouse, but they are definitely not required.

My recommendation, of course, would be some managed PoE switches. Used, if you must. Some used Cisco 3550 PoE switches on Ebay wont set you back that much, and they work great.

If your VoIP system is hosted, you'll need a new router, too. Your SonicWall won't work, unless they've upgraded their software to allow you to turn off their worthless SIP ALG.
Click to expand...

I can agree with a lot of this. Some customers really don't mind wall warts, but at 40 phones that's going to add up.

Edit: OP, on a $300 budget you are really screwed. What kind of business is this that can't put more of a realistic budget into their phones. Call me stupid, but in most business your phone is your livlihood.

Voice is a finicky beast. I am on a government revamp due to file transfers and even basic network traffic causing at the very least terrible call quality and at the peak, dropped calls.
 
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Your current setup will fail. Plan to do it right with PoE switches, Qos etc etc.

VOIP is definitely not plug and play for a corporate environment.
 
There some points you need to consider.

The bandwidth using G711 is about 83 Kbs. This does not include any overhead added by your WAN link. You still need some bandwidth for signalling. If you use presence features on the phones the signalling bandwidth needed can have large peaks.

Who is supplying the phones? If you supply them you need to check if they are supported by the company hosting the VoIP server.

If you are using new phones the Cisco 3550 POE switch may be a problem as its pre 802.3af, the standard for POE. I do not think some of the new phones will work with this.

Do the PCs and laptops that will be connected through the phones need Gigabit connections? Most of the IP phones that have the inbuilt switch only do 100 Meg.

What budget have you allowed for the phones? IN the UK the SPA504G is about £90. Some places will sell refurbed SPA942s for between £40 and £60. Even at the cheaper end of this that £1600 for the phones or about $2600. IP Phones, especially POE ones, are expensive, and if you find some cheap there is usually a reason. Do not touch Grandstream phones. Many of the older Cisco 7960 and 7940 phones come with SCCP, and not SIP. Getting the SIP firmware will need a support contract, its not available as a free download. Cisco do the SPA303 which has a switch so can be used with 1 cable to the desktop, but its not POE.

The router used will need to be able to prioritise the VoIP traffic on the uplink. If possible check with the ISP and see if VoIP traffic on you WAN link can be prioritised. This is available in the UK from some ISPs.

I have used the Cisco SMB SF 300 24 port and 8 port versions of these on quite a few VoIP installs, and recommend them. There is a 48 port version of this switch but I have not used it. In the UK the SF 300 24P POE switch is about £300 (about $480). The HP and Netgear switch usually work out more expensive. The SF 300 range are 100 Meg switches with Gigabit uplink ports. These work fine with the Cisco SPA500 range of phones, the older SPA942, Snom 300 and 370s. The are managed, have various different Vlan options (trunking, access, tagged and untagged), very good QoS, and if needed will do static routing at L3. I honestly do not think you will find something you need to manage that you cannot with these switches. The warranty is good with advanced next business day replacement.

If you really want to do this on the cheap buy some headsets and use a softphone on the PCs/Laptops. This will be on the same LAN as the data. Providing the SIP and RTP packets are correctly marked and the QoS on the switch is setup correctly, then the softphone and the usual PC traffic can work together OK. Doing things this way would save a great deal on the switch as non POE switchs are much much cheaper than POE. In the UK a POE switch costs more than twice as much as the same model non POE.

Rob.
 
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