Network design overkill?

[dcmbrown]

Our office is moving to a new building within the next couple of months and we're in the process of finalizing a number of things including the network. The building is 3 stories with approximately 250 drops spread out mostly over the top two floors with 3 drops per wall plate in most places for approximately 85 spots. Around 70 of these are designated for desks spots, while the rest are distrbuted for phones, printers, wireless, etc. We're a corporate web development firm so we a fair amount of audio work and some video but not a huge amount. I have no set budget to accomplish this as our IT department always seems to be a seat of the pants after-thought.

I've worked on a number of networks both large and small but have not had the chance to design one myself before.

Originally the plan as discussed with the architect was to create a combined data/voip gigabit network with a 10GbE fibre backbone with stacked switches on each floor to prevent having to have a foot or larger hole running between the floors for all of the cables for the drops ending in the server room. We could have a one inch hole for better use of space (not to mention fire regulations).
Is a 10GbE backbone on a gigabit network total overkill however? Right now we're running (slowly at times) on a 100MbE network to the desktop with a 1GbE connection to a couple of spots and between the servers (eg. our backup server and everything else). It's certainly possible we could need this sort of backbone in 5 years although mainly just in the server room where switches can simply be stacked.

On the otherhand, since coaxing up a ~$20k to ~$30k purchase may be difficult (since the upfront cost totals usually scare people even though it'd probably financed out at < $1000/month), I can probably build a 4Gbs or 8Gbs network using link aggregation for half the price.

Looking at VOIP calculations, it seems rather low that if everyone were talking to each other at the same time, we'd use less than 1.5MB/s (13440kbps) of bandwidth. I'm using this one here for a very rough estimate:
http://www.erlang.com/calculator/lipb/

 

[tipstir]

Our office is moving to a new building within the next couple of months and we're in the process of finalizing a number of things including the network. The building is 3 stories with approximately 250 drops spread out mostly over the top two floors with 3 drops per wall plate in most places for approximately 85 spots. Around 70 of these are designated for desks spots, while the rest are distrbuted for phones, printers, wireless, etc. We're a corporate web development firm so we a fair amount of audio work and some video but not a huge amount. I have no set budget to accomplish this as our IT department always seems to be a seat of the pants after-thought.

I've worked on a number of networks both large and small but have not had the chance to design one myself before.

Originally the plan as discussed with the architect was to create a combined data/voip gigabit network with a 10GbE fibre backbone with stacked switches on each floor to prevent having to have a foot or larger hole running between the floors for all of the cables for the drops ending in the server room. We could have a one inch hole for better use of space (not to mention fire regulations).
Is a 10GbE backbone on a gigabit network total overkill however? Right now we're running (slowly at times) on a 100MbE network to the desktop with a 1GbE connection to a couple of spots and between the servers (eg. our backup server and everything else). It's certainly possible we could need this sort of backbone in 5 years although mainly just in the server room where switches can simply be stacked.

On the otherhand, since coaxing up a ~$20k to ~$30k purchase may be difficult (since the upfront cost totals usually scare people even though it'd probably financed out at < $1000/month), I can probably build a 4Gbs or 8Gbs network using link aggregation for half the price.

Looking at VOIP calculations, it seems rather low that if everyone were talking to each other at the same time, we'd use less than 1.5MB/s (13440kbps) of bandwidth. I'm using this one here for a very rough estimate:
http://www.erlang.com/calculator/lipb/

Some of my accounts want to move faster 10, 100 and now 1000 is where most account clients want to be at. VOIP from Cisco was tested and now just sits in pile of dust. Cost to the client would be high, but right now the PBX Avaya system is cost effective now. Are you moving that much traffic through your company to go that extra mile to install GiG network. Slowdown you say right now how old are those routers, switches etc.. Now. Cost to update them won't be cheap!

 

[scotty]

I would say planning and things like traffic management are just as an important aspect given the type of office. I once worked as a network admin in a very similar office (internet design/multimedia studio), with lots of traffic going over the wire, VOIP, and the whole nine yards. I would say you're probably just as good off with a well planned design implimenting QoS and/or VLAN's for certain segments. We were running mostly 10/100 with a bit of GigE and after making sure our QoS and VLAN houses were in order, we rarely ran into issues.

And regarding your VOIP bandwidth calculation. It's a good rough starting point, but this is assuming everything going over the wire is running a compressed G729 codec. I dont know what kind of phone system you're going to be running, but not all phone systems will run purely over 1 particular codec, especially for internal calls. You may run G729 over the internet, but it's more common that systems run G711 internally, and that's more like 64+ Kb/s/u. Plus you have a little bit of overhead with most codecs and other information. A good 10/100 network can handle voip no problem though, so you're pretty safe either way. The most important thing with VOIP, especially in an office like yours, is QoS and VLAN'ing.

 

[tipstir]

Network Infrastructure at work is VLAN based just finished a project to remove rouge VLAN1 devices update IP/SM/DG then flip ports over to new switch. Not a easy task where you have research/locate/telnet over 5,500 nodes, I was the given management of the project, More like I did it all go to weekly network meetings telling them what's the status. Senior Network Engineers get too busy and getting no where too fast since 2005. The other project going on is the Network Refresh that's replaced current switches about 20,000 to cisco 3750G mix 24/48-ports all new switches have to be firmware updated with out script and tested. They get sent out to other locations around the USA.

No word on VOIP that's put on hold.. Once the Gig switches are in place then desktop support will have to put out the new DELL with GIG NICs. As for wireless it's still 54G based on Cisco equipment.

 

[dcmbrown]

So is there something specific then I should be looking for in a switch for QoS/CoS controlling VOIP over the network? (eg. a specific IEEE 802.? protocol?) There are stackable switches such as the Netgear GS748TS which claim to be usable for VOIP but I am somewhat suspect of due to their only port-based QoS policies. I'd rather not spend time reconfiguring a switch every time someone adds a phone to the network or moves it.

VLANing the VOIP phones and/or using protocol based QoS control (such as DiffServ) seems to be the way to go.

I would _like_ to use either Netgear GSM7300 series switches or a Dell PowerConnect 6200 series switches. These would at least provide the ability to upgrade to 10GbE should we ever delve deeply into video editing. On the otherhand a link aggregated 4Gbps network would probably more than sufficient as well so I've no problem with the Netgear GSM7200 series switches or the Dell PowerConnect 5400 series switches.

 

[tipstir]

So is there something specific then I should be looking for in a switch for QoS/CoS controlling VOIP over the network? (eg. a specific IEEE 802.? protocol?) There are stackable switches such as the Netgear GS748TS which claim to be usable for VOIP but I am somewhat suspect of due to their only port-based QoS policies. I'd rather not spend time reconfiguring a switch every time someone adds a phone to the network or moves it.

VLANing the VOIP phones and/or using protocol based QoS control (such as DiffServ) seems to be the way to go.

I would _like_ to use either Netgear GSM7300 series switches or a Dell PowerConnect 6200 series switches. These would at least provide the ability to upgrade to 10GbE should we ever delve deeply into video editing. On the otherhand a link aggregated 4Gbps network would probably more than sufficient as well so I've no problem with the Netgear GSM7200 series switches or the Dell PowerConnect 5400 series switches.

Those highend Netgear should work, we're also testing Nortel Switches since they can work in harsh conditions like were no A/C is available and dusty area's like in factory plant. I don't care for them but client wants to break away from Cisco high cost. I had attended a meeting about using centralize switch monitoring system by tyco electronics using a ninth wire to monitor about 20 switches in one network closet. Price tag would be over 1 million start but would have gone more as the cost for the Cat 5e or 6 cable with the 9th wire would be way over budget as each port would have to use the ninth wire cable also. If a switch or port goes down the system would send out a general alert to all parties, it would bring up CAD plans of the location where the switch is so you would know where you were going.

Of course using such a system would take away jobs though.. I am glad they didn't go with it..