10
votes
Accepted
Why does 10Gbps ethernet claim PAM16 encoding then use a squared DSQ128 constellation?
You're talking about 10GBASE-T - most other 10G flavors use straight 64b/66b (10GBASE-R), but that doesn't work on 500 MHz Cat 6A.
With 10GBASE-T, two consecutive PAM-16 levels (on each lane) ...
- 82.6k
10
votes
Accepted
SFP+ transceiver's ability to do 1GbE
Short answer: in theory yes, in practice no.
Long answer:
There are SFP+ optics which can also work at 1 GbE, I've talked (sorry, no other source than that) to people who were experimenting with it ...
- 186
7
votes
Enabling flow control on my ethernet NIC
You were closer than you think to getting it working. In fact the problem may have simply been that flow control wasn't enabled on the switch.
The ethtool source code (rev 3.18) and a register ...
- 81
7
votes
Accepted
Extremely long time to establish network link with Nexus N9K-C9372-PX-E
If you have a switch with a default configuration, spanning tree will block ports when they come up until the forwarding timer expires.
You can configure portfast on ports that have end hosts on them ...
- 67.1k
7
votes
Accepted
Why is there a separate set of 10 Gigabit fiber-optic transmission standards for WANs/SONET?
From IEEE 802.3 Clause 50.1: (emphasis mine)
The WAN Interface Sublayer (WIS) is an optional PHY sublayer that may
be used to create a 10GBASE-W PHY that is data-rate and format
compatible with the ...
- 82.6k
6
votes
Accepted
LC dual pair converter to 10GBASE-T
If using dual pair LC fiber to run 10GbE over a long distance, what's
the best way to connect it to a server on one end which has a
10GBASE-T port?
The best way is to get a server NIC with SFP+ slots ...
- 98.7k
5
votes
Accepted
Enabling flow control on my ethernet NIC
Most of this doesn't matter, ethernet flow control has never been widely supported and most switch devices will respect PAUSE frames, but not send them. That being said, your questions can be ...
- 508
5
votes
Accepted
Can I use a 40G transceiver in a QSFP56 NIC to connect to a 10G transceiver/switch if the NIC supports 10G speeds?
The only way you'd be able to keep using the same 40G QSFP is to get a 40G-SR4 and break it out to 4x10GE coming from the NIC and then connect one of those 10G's to your 4500.
Once you have a switch ...
- 6,104
4
votes
Accepted
What is the Difference between SFP+ and XSFP?
SFP+ modules leave more circuitry to be implemented on the host board whereas XFP or XENPACK implemented those circuitries inside the module.
Normally, you don't have to know that because you just ...
- 427
4
votes
10Gbase-T vs 10Gbase-TX
You can't find a standard for "TX" because there's no such thing. 10Gbase-T is defined by 802.3an-2006. I've never seen anyone call it "10Gbase-TX".
('tho there is a 10Gbase-T1 for ...
- 31.7k
4
votes
Accepted
Adapting 10GBaseT and NBaseT with a PoE Injector?
"NBASE-T" or "MGBASE-T" is any speed from 2.5GBASE-T or 5GBASE-T (sometimes including 10GBASE-T).
The best speed in common between a 10/100/1000/10GBase-T and a 10/100/1000/NBase-T ...
- 82.6k
3
votes
Reliable transfer but unreliable auto-negotiation?
You simply cannot mix shielded and unshielded parts in a link. The shield only works if it continuous end-to-end and properly grounded on both ends. The actual wires in shielded cabling cannot meet ...
- 98.7k
3
votes
Accepted
Would 1000BASE-T clients see benefits if connected to a 10GBase-T server via a 10Gbe switch
You would definately see a benefit. You are sharing the 1Gbit link to your server with several clients so your bottleneck would be a the 1Gbit link to your server. Once you have 10Gbit connected, that ...
- 2,016
3
votes
Would 1000BASE-T clients see benefits if connected to a 10GBase-T server via a 10Gbe switch
It depends on your bandwidth utilization. If your current 1G connections to the server are not fully utilized, then you won't get any benefit from 10G. Although there's nothing bad in 10G, it may be ...
- 1,133
3
votes
Accepted
SFP+ 10GBASE-LR and attenuator
Most 10 km PHYs can talk to each other even over very short links.
The key is whether the max launch power overshoots the max receive power, effectively blinding the receiver.
With this transceiver, ...
- 82.6k
2
votes
Router System Capacity Vs Packet Forwarding Capacity
We cannot know for sure what Juniper refers to when stating "system capacity 80gps"
If we take the embedded 4 x 10G interface and we use them at full duplex then we get 80gbps. So it could refer to ...
- 19.5k
2
votes
Cisco catalyst 45xx series compatibility with RG45 10Gb
I know that with the WS-C4507R+E supervisor, you can use the WS-X4712-SFP+E Catalyst 4500 E-Series 12-Port 10GbE (SFP+) line card. The SFP+ slots can use either 1 Gb SFP or 10 Gb SFP+ transceivers.
...
- 98.7k
2
votes
Single mode, single strand fiber handles 1Gbit but not 10Gbit
Try to link the pair of transceivers with a simple patch cable - not all of them are compatible and the wavelengths need to match (crossed over). There's no offical standard for 10GBASE-BR (as it ...
- 82.6k
2
votes
SFP to RJ45 for 10Gbit network
First a 10 Gbps network adapters use SFP+, not SFP.
Next, you can get a 10GBase-T SFP+ module for your adapter, rather than one of the fiber variants. In most cases, 10 Gbps adapters will have SPF+ ...
- 98.7k
2
votes
Fiber optic cable juniper ex4500
The OM3 fiber you linked to should do nicely, OM3 supports 10GBASE-SR for up to 300 m. As per Ron's comment, you should make sure that the fiber is crossed over - the (left) transmitter side needs to ...
- 82.6k
2
votes
Can 40GBASE-LR4 be used for 4x10G?
Just for people looking at this answer now (close to 3 years after the original answers): today you can get QSFP+ PLR4 transceivers that support 4x10G breakout over SMF (long range).
These ...
- 121
2
votes
Accepted
Latency of AOC vs passive DAC
The difference here is incredibly trivial - literally on the order of single-digit nanoseconds. The amount of time it takes to get the packet organized and across the switch is likely 2- to 3- orders ...
- 6,104
2
votes
SFP+ 10GBASE-LR and attenuator
Launch power max 0.5 dBm, receive power max 0.5 dBm. Should be fine. Also, -8.2 to 0.5 dBm is a huge range for launch power, although this may be specified with aging in mind (launch power reduces ...
- 493
2
votes
Accepted
Max cable length when using 10GBASE-T SFP+ transceiver
Yes, the transceiver actually reduces the maximum cable length.
This reduction is due to the maximum power draw of an SFP+ module of 2 Watt and 10GBASE-T requiring considerable power because of the ...
- 82.6k
2
votes
Accepted
Support for 10GBase-T RJ45 SFP+ transceivers
In many enterprises, switches and accessories are required to be under active vendor support. That leaves you with officially supported SFP modules and their support in switches.
Technically, using ...
- 82.6k
1
vote
How does Ethernet driver know if the cable is plugged in?
Link detection is specific to the physical layer.
The original coax Ethernet did not really have link state detection (some PHYs had a mechanism for detecting termination during transmission but it ...
- 13.1k
1
vote
Accepted
Intel x520 SFP+ connecting to a J9264A HP Procure 6600 switch
The Intel cards are usually agnostic when it comes to SFPs in my experience, but DAC-cables are a bit of a grey area since there's no standard governing them if I can remember correctly. So if you ...
- 2,249
1
vote
Cisco catalyst 45xx series compatibility with RG45 10Gb
From a quick glance at this data sheet, table 1 seem to indicate that your chassis and SUP support all line cards except the 24Gbps 47xx series.
So I may have missed one or two but it seems all these ...
- 2,638
1
vote
Accepted
What is your experience using 3rd-Party 10Gig Media Converters with Cisco equipment?
So the obvious question is how much all that media converter stuff costs versus just buying a cheap 10G NIC with an SFP+ port and using fiber, twinax or AOC to achieve a sane and supportable result? ...
- 6,104
1
vote
What is your experience using 3rd-Party 10Gig Media Converters with Cisco equipment?
Third party SFPs can be hit or miss. Make sure to check the compatibility matrix that cisco has.
If the module is an unsupported module then it will not work right off the bat. There is a command ...
- 547
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