[voip] Putting a voip setup on a flat network

[Oaktech]

One of my schools has an aging Toshiba POTS system which is getting increasingly unreliable. I've been asked by their headship to look into voip for them as a matter of some urgency.

 

Normally this wouldn't be an issue, but this particular school has about a dozen elderly unmanaged non-poe switches and no more than 1gig interlinks between switches.

 

We knew the day would come for this equipment, but it seems to have come now! All of this is budgeted and scheduled for replacement in the next academic year, but the current phone system is needing to be rebooted multiple times a week, sometimes a day and obviously this is becoming a safeguarding risk so I've been asked to look into it right now.

 

I know it's not advisable but does the hive mind think it's feasible for it to run satisfactorily for a few months on the flat network with POE injectors?

 

My other option is to make a huge fuss to my MAT to bring the switch and interlink work forward?

[ThatBoringBloke]

We have a few VOIP phones on our flat LAN. No one has ever mentioned it being an issue. That said we do have a 10Gb backbone.

[Aprice]

Possibly, however we have had many sites with flat networks that experienced call quality issues, Jitter - dropped calls e.t.c.

Implementing VLANS / QoS has resolved this in all cases.

 

I suppose it really depends on the number of clients on the network and just how much traffic there is, a small primary would probably not notice.

Edited January 11, 2023 by Aprice

[hallb15]

One of my schools has an aging Toshiba POTS system which is getting increasingly unreliable. I've been asked by their headship to look into voip for them as a matter of some urgency.

 

Normally this wouldn't be an issue, but this particular school has about a dozen elderly unmanaged non-poe switches and no more than 1gig interlinks between switches.

 

We knew the day would come for this equipment, but it seems to have come now! All of this is budgeted and scheduled for replacement in the next academic year, but the current phone system is needing to be rebooted multiple times a week, sometimes a day and obviously this is becoming a safeguarding risk so I've been asked to look into it right now.

 

I know it's not advisable but does the hive mind think it's feasible for it to run satisfactorily for a few months on the flat network with POE injectors?

 

My other option is to make a huge fuss to my MAT to bring the switch and interlink work forward?

 

Why waste time and money putting in a temporary solution if you can get the MAT to bring the switch work forward? - that would be my preferred option.

[Oaktech]

Possibly, however we have had many sites with flat networks that experienced call quality issues, Jitter - dropped calls e.t.c.

Implementing VLANS / QoS has resolved this in all cases.

 

I suppose it really depends on the number of clients on the network and just how much traffic there is, a small primary would probably not notice.

 

It's a fairly large primary - 600+ pupils, around 250 windows device 90 chromebooks. We'd be putting in about 40 phones.

 

I've just looked at the stats for the internet connection - we regularly run the 300/300 connection up to around 250 down so I'm not even confident that the internet connection will handle it.

[Oaktech]

Why waste time and money putting in a temporary solution if you can get the MAT to bring the switch work forward? - that would be my preferred option.

 

You are right - but it's not really that temporary - all the phones would stay, the PBX would stay, it would just be a config change to bring them onto their own vlan once the switches and interlinks were replaced.

[DavR]

I've just looked at the stats for the internet connection - we regularly run the 300/300 connection up to around 250 down so I'm not even confident that the internet connection will handle it.

 

 

Are you running full VOIP, or will you have a PBX onsite? If you've got a PBX onsite, then you only need to budget for however many external SIP lines will be using your Internet connection, as most of the calls will be internal. Voice data can be heavy, but not that heavy.

 

 

Definitely preferable to get the switch work done first though. I have seen phone and data traffic coexist happily on a flat network, but then, I've also seen schools have long arguments with their telco about who's to blame when they don't.

[Davit2005]

We had network noise from printers causing issues noise with VOIP phones at a previous place when we put them on the same vlan. We don't seem to have the issue now but maybe it was those specific printers (mostly HP 2055's I think) and phones.

[psydii]

Definitely push to bring the switch work forward, if its budgeted for next year then the only thing Finance have to worry about is cashflow in the short term, and a 600 seat school LAN* should easily be absorbable in the cash reserve.

 

If that isn't going to be possible, you might want to have a play with firewall / qos rules to see if you can give traffic to/from the phones priority. but without vlans or a separate IP range for them I'm not sure that is possible, unless the phones can qos tag their traffic onto the LAN and then the router/firewall make the necessary priority changes in its queue. I've done something similar once and it seemed to improve things enough to get the problem off my back for a few months ahead of moving to a 1000/1000 link.... but to be honest it may also simply have been luck.

[Oaktech]

Are you running full VOIP, or will you have a PBX onsite? If you've got a PBX onsite, then you only need to budget for however many external SIP lines will be using your Internet connection, as most of the calls will be internal. Voice data can be heavy, but not that heavy.

 

 

Definitely preferable to get the switch work done first though. I have seen phone and data traffic coexist happily on a flat network, but then, I've also seen schools have long arguments with their telco about who's to blame when they don't.

 

 

Having run both an onsite FreePBX and a hosted 3CX install at other sites I'd be very much favouring having an onsite PBX as having to go through the host's helpdesk to rename a directory entry every time someone moves desks is a monumental PITA

 

I've messaged the MAT and CC'd SLT to see if the MAT can arrange their guy to do cable works at Feb half term and if they can get stock of the switches they were suggesting.

[chaplic]

even if you're being generous, voice is going to take up 64kbits/sec or thereabouts but you will have a possible avaialbility risk against a guaranteed ​ of the current POTS. Also if the POTS system died, could you even get spare parts?

[DavR]

Having run both an onsite FreePBX and a hosted 3CX install at other sites I'd be very much favouring having an onsite PBX as having to go through the host's helpdesk to rename a directory entry every time someone moves desks is a monumental PITA

 

When we replaced our phone system, we got an onsite PBX and reused all of our existing handsets. Saved us a fortune versus going for fully hosted VOIP and a monthly subscription for every handset.

[Oaktech]

even if you're being generous, voice is going to take up 64kbits/sec or thereabouts but you will have a possible avaialbility risk against a guaranteed ​ of the current POTS. Also if the POTS system died, could you even get spare parts?

 

This is the situation we're in - an 8 way card died in it about a year ago, the supplier came out and looked, said they had 'one in stock' and then we got a package 2 weeks later that had clearly been bought off eBay and sent straight to us! We contested the hell out of that because the invoice from eBay was in the package and the supplier attempted to invoice us fully 3 times what was on the paperwork in the box in addition to the callout to assess it and install it!

 

The conversation with the MAT is now also including the option of a secondary line that can also be used as a failover!

[supportman]

We run our teams IP phones on a "flat" network. No issues whatsoever.

[Chris_Cook]

Its all going to depend on how busy the network is.

 

On of our primarys is fine on a flat network, but its probably half the size of yours.

 

You might want to talk to spitfire communications - http://www.spitfire.co.uk. We are hosted with them, but we have access to the management console for day to day changes etc. They also have supported on prem for us in the past.

[Ex-MGSTech]

I think you are likely to run into QOS issues without being able to VLAN off the VOIP traffic.

If you are already maxing out your broadband, adding a SIP trunk or two to the mix won't help!

 

We pout in a local LG iPECS Ip system about a year ago, don't forget if you only havbe 1gb uplinks between switches, local traffic will eat that up easily withoiut going near your SIP tuunks.

 

We are in the process of upgrading from a 10gb backbone to a 25gb backbone!

 

Maybe the new DfE digital standards document might help your cause? https://www.gov.uk/guidance/meeting-digital-and-technology-standards-in-schools-and-colleges/switch-standards-for-schools-and-colleges

[Oaktech]

I think you are likely to run into QOS issues without being able to VLAN off the VOIP traffic.

If you are already maxing out your broadband, adding a SIP trunk or two to the mix won't help!

 

We pout in a local LG iPECS Ip system about a year ago, don't forget if you only havbe 1gb uplinks between switches, local traffic will eat that up easily withoiut going near your SIP tuunks.

 

We are in the process of upgrading from a 10gb backbone to a 25gb backbone!

 

Maybe the new DfE digital standards document might help your cause? https://www.gov.uk/guidance/meeting-digital-and-technology-standards-in-schools-and-colleges/switch-standards-for-schools-and-colleges

 

The plan and budget to get up to spec is already in place - it was just a question of whether we would have to bring the whole plan forwards to right now, or whether we could jump the gun with what we had and get rid of the troublesome Tosh system in the very, very near future - the words 'next couple of weeks' were used by SLT!

[2ilent8cho]

If you want an idea of how much data a SIP trunk will use this is ours. Look at the entries in the list with voip in the address name, this is over 7 days to our onsite PBX. The SIP trunk is for 10 lines and the PBX has 150 extensions (though extensions to PBX traffic is not show here, this is purely the trunk). We have around 1500 calls a day both internal and external processed by the PBX.

 

[Darkheart]

You are right - but it's not really that temporary - all the phones would stay, the PBX would stay, it would just be a config change to bring them onto their own vlan once the switches and interlinks were replaced.

 

If you don’t have PoE now, you could buy VoIP phones with power supplies. I did this with Yealink phones we are deploying. I have rooms that don’t have enough network points and need mini switches. Adds to the cost, but it wasn’t much when bought together with the phone. Less than the cost of PoE injectors in my case.

[dmj]

The plan and budget to get up to spec is already in place - it was just a question of whether we would have to bring the whole plan forwards to right now, or whether we could jump the gun with what we had and get rid of the troublesome Tosh system in the very, very near future - the words 'next couple of weeks' were used by SLT!

 

I guess question is if the current system is broken, will adding a new system to a broken network make the phone system less broken or more broken?

I'd go for it, if it gets them them out of a hole at the cost of some call latency it's probably worth it, then you can come a long and be a hero by fixing it with the new network.

[Oaktech]

If you don’t have PoE now, you could buy VoIP phones with power supplies. I did this with Yealink phones we are deploying. I have rooms that don’t have enough network points and need mini switches. Adds to the cost, but it wasn’t much when bought together with the phone. Less than the cost of PoE injectors in my case.

 

I've got an actual pile of POE injectors from another school - we bought that school 60 unifi APs and they all came with injectors I don't need because that school is already fully POE+ at every switch!

[Oaktech]

Okay, we're a year down the line from this thread and I'd just like to provide some closure...

 

Upon further investigation with our Finance dept, we had a long standing maintenance plan (we'd paid it continuously for almost 15 years!) that our POTS supplier was trying to wriggle out of fulfilling due to the age of the equipment. We ended up getting legal advice on that plan, and once enforced with a solicitors letter, meant that they they were obliged to provide us a reliable, working system until such time as the plan expired, so they did a lot of work towards the end of Jan to replace one of the Toshiba chassis and also got BT to repair one of our ISDN lines. That made our POTS system reliable for the remainder of the academic year.

 

During the summer holidays we ripped out all the unmanaged switches and replaced with POE+ Unifi switches, plus repairing a lot of to-the-desk cabling and a couple of interlinks. We set up quite a few VLANs during that process, for phones, copiers, and guest wifi. We then had a Splicecom VOIP unit installed by our Trusts's preferred supplier using Yealink handsets.

 

We had a few teething issues that were dealt with by a combination of me adjusting QoS and some firmware updates by the supplier.

 

We are still awaiting a SOGEA backup line that was part of the project!

Edited January 17, 2024 by Oaktech

[mavhc]

Step 0 is get some data from your switches to find out if/when they're maxed out

 

That said my switches are 15 years old and I run voip phones without vlans, and half of them via a site-to-site vpn, and the only time it went wrong was when ISP was being DDoS'd

[Olliedawg]

We run voip on a semi "flat" network. Only VLANS we have here are for :

• Guest Network
• Student Network
• IoT Network (Tills, Display TV's, Vending..)

Never really had any issues at all with ours. All switches are managed, with minimum 1gbps uplinks between them

[timbo343]

Our primary schools used to run VOIP over their flat networks with their phone systems on premise. There was never an issue.

 

Since setting up VLANs for the new cloud 3CX system for the trust, the phones use a max of 20kb - it's very little overhaul on the network.