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Anav
Sarcastic Llama? Naw, Just Acerbic
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join:2001-07-16
Dartmouth, NS
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reply to Brano

Re: IPTV Possible on USG??

Good point!


OGalati

join:2005-08-19
Argentina
reply to Anav

Sorry if I didn't understand the thread, but AFAIK QoS and 802.1p tagging is meaningless to solve the Vlan34/35 issue mentioned earlier. What you need is 802.1q tagging. Maybe the switch don't tag packets for 802.1p, but yes do tag for 802.1q purposes.

Regards.


JPedroT

join:2005-02-18
kudos:1

said by OGalati:

Sorry if I didn't understand the thread, but AFAIK QoS and 802.1p tagging is meaningless to solve the Vlan34/35 issue mentioned earlier. What you need is 802.1q tagging. Maybe the switch don't tag packets for 802.1p, but yes do tag for 802.1q purposes.

Regards.

According to sources familiar with the IPTV setup for the ISP that Anav uses, frames with the wrong p-bits set, will get dropped or something similar.

I agree with you, that vlan 34, 802.1q tags are the important part here, but hey, the ISP can build their network just how they want to
--
"Perl is executable line noise, Python is executable pseudo-code."


mozerd
Light Will Pierce The Darkness
Premium,MVM
join:2004-04-23
Nepean, ON
reply to mozerd

Click for full size
said by mozerd:

The Netgear GS108T can actually apply tags

Anav See Profile after defining your vlan's you then work with QoS to prioritize the traffic with a technique called class of service (CoS) which is a 3-bit field called the Priority Code Point (PCP) ... It specifies a priority value of between 0 and 7 inclusive that can be used by QoS disciplines to differentiate traffic -- this technique is commonly referred to as 802.1p --- so in the Netgear GS108T you can set the priority value as defined inn the Manuel -- and partly shown in the graphic above.

The issue is how has YOUR ISP defined that priority value and is that priority value recognizable by the port/vlan it hits -- If the ISP is not using proprietary code then you should be good to go but I HAVE my doubts.

BTW, in clear terms WHAT is your objective? Do you want to be able to stream IPTV to multiple devices inside your home
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business


Anav
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Hi Mozerd, as I stated nowhere does it say it tags 8.02.1p.
(1) Dlink states "ASSIGN" priority
(2) Netgear states "Map" priority.

Unless someone can test, I cannot assume those terms mean tag. Other more expensive switches say tag for example.

Olagati, as JP noted, the ISP required a setting of 4 or higher I believe.

Mozerd no its not some obscure proprietary setting. The Asus N56 Linux code was modified for this requirment its set to tag the packets at level 4 802.1p.

Purpose, academic interest for me, but if feasible I will procure a switch and borrow an STB to play. I have a friend who need to replace their Bell fibreop action tech so I am sorting out the possibilities.

I am also helping a person out in the US on FIOS FTTH with an ONT, an actiontech but there setup is a tad archaic, coax from ONT to STBs and DVRs, ethernet and coax to action tech for internet and the coax for setup guide orderming movies etc. My local friend has ethernet to everything, much cleaner

By the way this fios link may be of interest to some..
»Verizon Online FiOS FAQ »What are the tradeoffs between the various router configurations (especially options 6-8)
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment



mozerd
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Nepean, ON

said by Anav:

Hi Mozerd, as I stated nowhere does it say it tags 8.02.1p.
(1) Dlink states "ASSIGN" priority
(2) Netgear states "Map" priority.

Unless someone can test, I cannot assume those terms mean tag. Other more expensive switches say tag for example.

In Netgear for video you would MAP to the hardware queue "4" or NORMAL so it tags that "queue" and looks for packets to match --- will the Netgear TAG the IP PACKET = NO --- WHY would it? Its a hardware QUEUE on the VLAN.
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business

JPedroT

join:2005-02-18
kudos:1

The point is that the q and p bits on the ethernet frame need to have specific value to be accepted by the upstream switches. IE Anav needs the frames coming from the STB to be tagged or if it already is tagged then some sort of vlan translation.

So just putting into one of the hardware queues on a switch, will not be enough unless its also tags it with the right bits.
--
"Perl is executable line noise, Python is executable pseudo-code."



Anav
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Thank you JP, exactly. It scares me when you agree with me. I have to pinch myself and ensure someone didnt spike my coffee with mescaline. I am not usually enlightened.

After carefully reviewing the Zyxel GS2200-8, I am starting to believe that managed switches are not capable of actually tagging data packets with 802.1P. It appears, the way I read it, that the zyxel is like the DLINK and Netgear but explains it a bit better.

What I mean is that the Zyxel is able to read an 802.1p tagged packet and it maps ITS OWN EQUIVALENT priority queue according to its table that is mapped one to one to the standard. Thus it respects the standard but applies physically its own internal routing priority.
For data without priority tagged packets, the switch allows you to assign AN EQUIVALENT, zyxel phsyical queuing number, to what it should be in terms of the standard if it had tagged data packets.

In other words it manipulates the data as if it actually had 802.1p packets, to the level the admin desires.

Conclusion, even the GS2200-8 does NOT tag packets. I suspect the same schema for the Dlink and Netgear which talk about assigning and mapping (similar language on the zyxel). The only difference that I see between the zyxel and the other is that they actually break out equivalent mapping 1:1 to the standard wherease the other two lump the standard into groups of two and use generict text names.

Pictures next post........
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment



Anav
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Click for full size
Click for full size
Click for full size
.....

JPedroT

join:2005-02-18
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1 edit

The ZyXEL tags just fine, just like on the USG you got tons of stuff including policy rules and classifiers if you want to get fancy



Anav
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Unfortunately, I dont agree with your assertion based on the language used in the Manual. They clearly IMHO state that they physically apply their own proprietary routing but equivalent to the standard.

The switch is able to read the tagged data packets and then actually applies their own table (and own proprietary physical routing proirity schema) to control the data flow. I repeat it does NOT use the 802.1p tagging to actually do anything (it doesnt use the standard it only reads it). For untagged packets it allows the admin to assign phsyical routing-control via the zyxel priority assignment (which one can equate to 802.1p via the mapping table).

Perhaps your thinking of a different switch, because I dont see any other logical explanation that states differently.
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment


JPedroT

join:2005-02-18
kudos:1

I got one under my tv

Chapter 8.7 Port Setup in the UserGuide, here you set the Priority number/tag/bits for all frames that does not have already have a priority tag.
--
"Perl is executable line noise, Python is executable pseudo-code."



Anav
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Which Switch and prove it.

Put an untagged packet through the switch assign priority 4 and then unwrap the packet afterwards. Nothing in the manual says it actually tags a data packet.

Show me the quote about it physically tagging the data packet??
I hope your right, really.
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment



mozerd
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Nepean, ON

2 edits

1 recommendation

reply to mozerd

said by mozerd:

In Netgear for video you would MAP to the hardware queue "4" or NORMAL so it tags that "queue" and looks for packets to match --- will the Netgear TAG the IP PACKET = NO --- WHY would it? Its a hardware QUEUE on the VLAN.

Apparently I was wrong -- For the Netgear GS108Tv2 and using firmware version 5.x utilizing DiffServ the switch will insert p tags:
Page 287 of the manuel

Marking CoS (802.1p): sets the three-bit priority field in the first/only 802.1p header to a specified value when packets are transmitted for the traffic class. An 802.1p header is inserted if it does not already exist. This is useful for assigning a layer 2 priority level based on a DiffServ forwarding class (i.e., DSCP or IP Precedence value) definition to convey some QoS characteristics to downstream switches which do not routinely look at the DSCP value in the IP header.

So the firmware version is important with this particular version of the GS108Tv2 --- if you're going to buy one of these make sure that its the v2 --- firmware version 5 is readily available in the Netgear Support area.

You can read the Manuel here using firmware v5.x --- page 288 titled DiffServ Example Configuration
--
David Mozer
IT-Expert on Call
Information Technology for Home and Business

JPedroT

join:2005-02-18
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2 recommendations

reply to Anav

Click for full size
Ze Manual


Anav
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reply to Anav

Nice find Mozerd, I didnt go so far as to read the diffserv section. I will have a closer boo to see if an be used the way I am thinking.

As for JPed, sorry mate, your at a disadvantage, english not being your native tongue. I already quoted that particular graphic. It clearly states it applies the zyxel proprietary value. It does not tag with the 802.1p standard. Try again.


JPedroT

join:2005-02-18
kudos:1

said by Anav:

Nice find Mozerd, I didnt go so far as to read the diffserv section. I will have a closer boo to see if an be used the way I am thinking.

As for JPed, sorry mate, your at a disadvantage, english not being your native tongue. I already quoted that particular graphic. It clearly states it applies the zyxel proprietary value. It does not tag with the 802.1p standard. Try again.

You need to explain that, because nowhere does it say proprietary there. It inserts the priority value that is set in that field.
And then it refers to a table that shows a menu which lets you configure which hardware queue a frame with a certain priority value will be stuffed into.
--
"Perl is executable line noise, Python is executable pseudo-code."


Anav
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2 edits

It doesnt say proprietary directly but read it again.

Under prioriity queue assignment
First Para - Defines what IEEE802.1P is. Thats all.
Second para - States the switch has eight physical queues (this is a switch programmed functionality). You can map these switch (AKA PROPRIETARY methodology) physical queues they call them Priority VALUES, to the standard 8 priority levels described in 802.1p.
The switch allows one to assign physical queues-Priority Values that correspond to the 802.1p priority you would like to MIMIC!!
There is no tagging of frames.

Now contrast that with the text in the Netgear manual.....
3. Configure the policy attributes:.
• Mark CoS. Enter the specified Class of Service queue number to mark all packets for the associated traffic stream with the specified class of service value in the priority field of the 802.1p header. If the packet does not already contain this header,
one is inserted. The CoS value is an integer from 0–7.
From the Class of Service field, set the CoS tag value to be reassigned for packets received on the Voice VLAN when Remark CoS is enabled.

--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment



Anav
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1 edit
reply to Anav

In more detail, the netgear BASIC CoS is what all the others are doing........
Basic CoS Configuration
Use the Trust Mode Configuration page to set the class of service trust mode of an interface. Each port in the switch can be configured to trust one of the packet fields (802.1p or IP DSCP), or to not trust any packet’s priority designation (untrusted mode). If the port is set to a trusted mode, it uses a mapping table appropriate for the trusted field being used. This mapping table indicates the CoS queue to which the packet should be forwarded on the appropriate egress port(s). Of course,
the trusted field must exist in the packet for the mapping table to be of any use, so there are default actions performed when this is not the case. These actions involve directing the packet to a specific CoS level configured for the ingress port as a whole, based on the existing port default priority as mapped to a traffic class by the current 802.1p mapping table.

802.1p. The eight priority tags that are specified in IEEE 802.1p are p0 to p7. The QoS setting lets you map each of the eight priority levels to one of four internal hardware priority queues: High, Normal, Low, and Lowest.

So its clear that only in the setting policies for Diffserv in the netgear switch, is one actually permitted to assign and tag 802.1p frames in data packets.
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment


OGalati

join:2005-08-19
Argentina
reply to Anav

said by Anav:

It doesnt say proprietary directly but read it again.

Under prioriity queue assignment ......

That is a mere general reference to switch features, not an exhaustive explanation.

JPedroT's graphic quotation refers to incoming frames section.

Check chapters 20-21.
»ftp://ftp.zyxel.com/GS2200-8/user_guid···0-8_.pdf

You have there the way to classify traffic and the actions you can take over that classified traffic at the egress time, mainly VLAN tagging and priority tagging.

Regards.


Anav
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Listen, just because Messi Plays for my fav team Barca, does not mean I have to agree with you. Furthermore HOWDARE (joder) you side with that upstart JP obviously hiding in Norway for some reason, instead of a fellow American (you know that North and South American free trade and bonding).

You are partiallly correct. The switch does do vlan tagging and actually changes the data packets. However, I disagree with respect to 802.1p. the Switch does not actually tag packets, but concur it can read them but read on..........

The switch according to how I read the manual.
a. has a mapping table of its priority values physical queues to the standard values 802.1p (this table is strictly for the user to to be able to setup the zyxel values IAW with how they want actual 802.1p packets to be handled and has no actual taggin function just a translation function)
b. the switch knows what the physical priorities are as assigned by the admin. These will be applied to port traffic or vlan traffic.

Now two cases can occur when a traffic arrives or lets say egresses an interface.

(i) It has an 802.1p tagged data
Here the switch which can read the tagged data point but does no direct physical function based on 802.1p. Instead, the switch then uses the mapping table translates it to the physcal queue setting that the user admin put for that 802,1p level ABD THEN ensure proper priority routing. - the switch then treats or maniuplates that data according to the user schema.

(ii) It has no 802.1p tagged data
Here the switch is screwed because no Tagged data is detected.
Luckily the admin has defined a default setting for such data. The switch detecting an untagged packet goes to its admin setting and sees a priority default has been enabled (for that port or vlan) and then applies one of the zyxel PHYSICAL security priority queues to that data. It does not tag it, it simply maniplates it, ie prioritized it internally IAW with the rest of the traffic as per the admin priority routing table.

In both cases above its not the 802.1p that manipulates the datas through the switch in terms of priority. It is the zyxel priority physical queue settings which determine traffic priority flow. If the data is tagged, the switch reads it translates it and then carrys out actions. If untagged, the switch apples a default and carrys on.
--
Ain't nuthin but the blues! "Albert Collins".
Leave your troubles at the door! "Pepe Peregil" De Sevilla. Just Don't Wifi without WPA, "Yul Brenner"

LlamaWorks Equipment



Anav
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reply to Anav

Im still waiting for Proof. You know those jpegs that JP is going to post showing an untagged packet arriving at his switch and then the next showing a data packet now tagged with 802.1p level four. No cheating allowed (like using a cisco switch LOL).


JPedroT

join:2005-02-18
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3 edits

I think you need to revisit some stuff here, because a switch can have more or less queues than there are p bit values.

So you need to define which hardware queue that should get your frame with p bits xyz and abc and ghj etc etc.

The next point, what is a queue? Its just a memory buffer where we store frames and can select which frames should be sent out in which order, based on what you ever disciplines your switch supports SFQ, RRB and WRRB etc. And we use multiple queues to "sort" the frames, the better your switch the more queues you have.

I can definitely do some traces, but it wont happen very quickly. Since I drowning in work, the Chinese New Year week is a week I might be able to get some head way into my pile of backlogged tasks

And of course »www.ingress.com/ takes up a lot of my spare time

--
"Perl is executable line noise, Python is executable pseudo-code."



Anav
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reply to Anav

Too funny JP. I was just thinking that since your so rich, you should fly me to Taiwan and we can meet and discuss the switch architecure at the Poodle Park ( I cant pronounce it properly) where zyxel hq resides. No worries mate. Take your time. Avoid the beer bath, less likely to drown although I hear its really good for the skin.


JPedroT

join:2005-02-18
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Why do you want to go to Taiwan?

And if I was rich, I would have been able to tell somebody to do the test and I could post and claim the credit


Kirby Smith

join:2001-01-26
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reply to Anav

May I try to blow some fresh air through the llama intransigence and suggest that in order for prioritization to be useful, a managed switch has to set the priority bit for the router to know that QoS is wanted. How could a router otherwise achieve the priority goal? It is my expectation that any reasonably useful managed L2 switch will set the bit, no matter how awkwardly the user manual is written. Whether a particular application actually needs QoS to achieve functionality is another question.

kirby



Anav
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reply to JPedroT

said by JPedroT:

Why do you want to go to Taiwan?

And if I was rich, I would have been able to tell somebody to do the test and I could post and claim the credit

Ha, the Taiwan was merely bait. Now that I know your ready and willing to pay me to go to elsewhere, suggest Valencia is nice this time of year.

JPedroT

join:2005-02-18
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You stopped reading after the first sentence?



Anav
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Just testing how much free time you really have. Could of traced 5k untagged data packets by now .