Community discussions

 
User avatar
bigcw
Member Candidate
Member Candidate
Topic Author
Posts: 105
Joined: Mon Sep 08, 2014 2:38 pm

"crs317 - improved transmit performance between 10G and 1G ports"

Wed Jul 25, 2018 5:09 pm

Hi Mikrotik support

"crs317 - improved transmit performance between 10G and 1G ports"

^^ this is a line from the changelog starting from 6.42rc6 and 6.41.1.

Are you prepared to provide any more detail on this issue, please? In other words, what symptoms were there that needed to be fixed?

Reason for asking is that we have a poorly performing 1G link from a CRS317. It is fast (line rate) when the CRS receives data, but slow (circa 250mbps) when transmitting. It runs 6.41rc38*. Is this poor performance likely to be caused by the same problem you fixed?

*I wouldn't usually put an RC version into production, but it seems the CRS317 was released without VLAN switching support and the only way to get it (in hardware, not using a software bridge) at the time was to run the RC version.

Thanks, Chris
Ecom International Network - Operators of AS61337 with POPs in Europe and North America - www.ecomltd.co.uk
Colocker Data Centre - The data centre with a difference! - www.colocker.com
 
User avatar
bigcw
Member Candidate
Member Candidate
Topic Author
Posts: 105
Joined: Mon Sep 08, 2014 2:38 pm

Re: "crs317 - improved transmit performance between 10G and 1G ports"

Fri Aug 03, 2018 2:27 pm

Nobody answered on here, and Mikrotik support (email) refused to give me any help.

So last week I put in a maintenance notice to clients and then on Tuesday night at midnight I drove 100 miles to the data centre, messed around with site security, got to the rack where the CRS317 was. At 2am I updated the firmware and rebooted the switch. Then did exactly the same on a second. 0300 I set out back for home, was in bed for 0530.

This was a risk. Had I done the above and fixed the problem I would have not thought about it again. If it didn't I would have been mightily p%$&ed off... as you can imagine, to the point that the switches would probably have been replaced.

Luckily for me it did fix the issue.

But this raises the issue yet again: why can you not be a bit more supportive, Mikrotik? I have something like £100k worth of your kit either belonging to my company or managed by us and this is your flagship, most expensive switch model. Sure we're not your biggest customer, but we're not a one-person consumer either. I ask a pretty basic question and you refuse to give me any help. I'm a huge advocate of your equipment, and I really want to keep using it, but minor, silly issues and getting effective support in a reasonable timeframe is a constant frustration. Please consider investing time and money into providing decent level technical support even if it is only available to larger and/or proven technical competent customers.

Chris
Ecom International Network - Operators of AS61337 with POPs in Europe and North America - www.ecomltd.co.uk
Colocker Data Centre - The data centre with a difference! - www.colocker.com
 
MrYan
Member Candidate
Member Candidate
Posts: 109
Joined: Sat Feb 27, 2010 6:13 pm

Re: "crs317 - improved transmit performance between 10G and 1G ports"

Fri Aug 03, 2018 11:21 pm

Usually where there is a large mismatch in speed, the issue is down to lack of buffers. If you have packets arriving at 10 Gbps and need to send to a port that is only 1 Gbps you need to absorb the burst to stop TCP slowing down.

If I had to guess, this would be the problem that was resolved (or mitigated).
 
User avatar
bigcw
Member Candidate
Member Candidate
Topic Author
Posts: 105
Joined: Mon Sep 08, 2014 2:38 pm

Re: "crs317 - improved transmit performance between 10G and 1G ports"

Tue Aug 07, 2018 11:20 am

Usually where there is a large mismatch in speed, the issue is down to lack of buffers. If you have packets arriving at 10 Gbps and need to send to a port that is only 1 Gbps you need to absorb the burst to stop TCP slowing down.
I'm aware of what the issue (likely) was. My question to Mikrotik was 'have you fixed this yet?' and my rant in the post above was because they refused to answer.

Let's not get started on whether their flagship switch model should have been released with such a bug present. I mean, surely 1G to 10G performance was tested given there will clearly need to be some buffering going on. Then again, they also released it without is supporting VLAN trunking (in hardware) or interface bonding, stuff I would consider pretty essential to any half-decent managed switch let alone a flagship model so I guess anything is possible.

It is unfortunate that this behaviour is what we have come to expect from Mikrotik.
Ecom International Network - Operators of AS61337 with POPs in Europe and North America - www.ecomltd.co.uk
Colocker Data Centre - The data centre with a difference! - www.colocker.com

Who is online

Users browsing this forum: No registered users and 85 guests