1Gbps Copper TAP vs SPAN between ONT & Router

[Pucelle]

I am looking to put a TAP on my WAN connection as I want visibility into my traffic before any filters/QoS/etc are applied behind my router. I also want to beable to document changes as I start building out my home network and labs.

The connection is a 500/500 Fios connection going between the ONT and my router. Since the connection is below the 1G wirespeed of the line, I've been told that I do not have to worry about latency but I haven't been able to find much information regarding that. A coworker stated that if I use a cat 6 cable that should take care of any worries there.

In addition, in researching a copper tap, most people are saying to just put a managed switch there and SPAN the traffic as that would be cheaper than a dedicated TAP. However, that's not really the case on 1G+ copper connections which can drop a lot of the packets causing high retransmits. Since this will be located within an 18" SMC enclosure, heat and space would also be a concern. While at the moment there's only a single connection after the router (wireless router), eventually there will be 3 total (2 copper & 1 Fiber) with no need for a switch within the enclosure. Since this is for the WAN connection, it's for all traffic going to and from my location.

Are there any recommendations on a good Gigabit Copper Tap? Is it still recommended that I use a small managed switch instead? What switch would you recommend?

 

[coxhaus]

Use a switch and mirror the router port. I think all the Cisco switches will do this. I am sure there are other switches.

The problem is how to process all the data.

 

[MichaelCG]

A coworker stated that if I use a cat 6 cable that should take care of any worries there.

Your coworker is incorrect. Cat5e, Cat6, or Cat7 will all have the same latency and performance for a 1Gbps connection.

What are you going to process this data stream with? Do you have a PC that can handle this kind of bandwidth in real time? What is your overall goal? What are you looking for? Would you be better served by just building an x86 firewall and doing PCAPs off the WAN interface as needed?

The last copper 1Gbps tap I purchased was for work and it was for sure not in the price range of a typical home geek user. It was a Net Optics 1Gpbs copper tap and I think it was around $1000, but this was 5'ish years ago.

As for a managed switch that can do port spanning? I agree with Coxhaus that most Cisco enterprise switches can support that usually. Can't be more specific since I haven't tried to do this outside of the large Enterprise in a very long time. We have taps all over with Gigamons aggregating and distributing to various monitoring systems. Our network team generally frowns upon span ports....but that is an Enterprise issue not a home tech user issue.

 

[follower]

Your coworker is incorrect. Cat5e, Cat6, or Cat7 will all have the same latency and performance for a 1Gbps connection.

That's not true.

 

[ColinTaylor]

That's not true.

Why not? 1Gbps is 1Gbps.

 

[follower]

Why not? 1Gbps is 1Gbps.

Performance doesn't mean 1 Gbps. 1 Gbps means max speed. There are many variables for the performance.

 

[Pucelle]

SPAN ports drop too much traffic and have a lot of retransmits at high speeds hence looking at the TAP. Since the wirespeed connection is at 1G but the traffic is capped at 500Mbps does that mean there will be no noticible latency on that connection? Or am I wrong in where that limit is applied, the Router-ONT connection is 1Gbps while the connection from ONT-ISP is limited to 500/500 on the Fiber cable so the bottleneck would be on the ONT vs the Router. I though the 500/500 limit is applied on both connections of the ONT.

The speed limits for Cat5e, Cat6, Cat6a, Cat8 are all different so if the max speed the line can handle is higher than the speed going across the wire, how does that affect latency or throughput?

Anyone have any exerience with Dualcomm TAPs?