Greetings to everyone! We are planning to upgrade our HP switches in preparation for our VoIP deployment. Does HP switches supports port sharing for voice and data with different VLAN (access & voice)? What HP switches you recommend for this setup?
I'm planning to do port sharing (connect IP Phone in the switch and connect the desktop at the back of the phone) to eliminate cabling cost and also this is the typical way of deploying VoIP nowadays. Is the configuration above sufficient to have a separate VLAN for voice and data? What is the equivalent of CDP in HP? Any effect to the quality compared of separate switch port for IP Phone and dekstop?
Yes, if you have data VLAN untagged and voice VLAN tagged, that is exactly the same as have a Cisco Access port in Data VLAN with "Voice VLAN XX" on the port.
HP Can have CDP enabled, but you would normally use LLDP.
The "separate switchport for IP phone & desktop" idea is an idea that technically-illiterate idiots and incompetents come up with. Ignore them.
vince, are you sure there is no "voice" command? it's been a while since i've configured an HP, but i could have sworn that there was a voice specific command under the vlan config?? not that it matters since you still have to do one tagged and one untagged...
I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)
I'm in now way the expert on Procurves, but I am familiar with the command on Ciscos, and I would have thought I would know it if Procurve had it as well.
SB-1-SG044-SW22(eth-C19)# vlan 249 ?
<SNIP lots of output>
voice Labels this VLAN as a Voice VLAN, allowing you to separate, prioritize, and authenticate voice traffic moving through your network.
No idea what it does, so I won't apply it!
I'll look it up.
Well, the config guide just says "see p2-60", but that section of the manual just explains all the normal dot1q tagging and QoS (none of which has anything to do with the "voice" command as far as I have experienced), so I still have no idea what the "voice" command actually does for you.
You can see when you do a sh vlan:
I'll ask my friendly local Procurve bloke and get back to you.
SB-1-SG044-SW22(eth-C19)# sh vlan 249
Status and Counters - VLAN Information - VLAN 249
VLAN ID : 249
Name : VLAN249
Status : Port-based
Voice : No
Jumbo : No
See below for the manual:
Voice VLANs
Configuring voice VLANs separates voice traffic from data traffic and shields your voice traffic from broadcast storms. This section describes how to configure the switch for voice VLAN operation.
Operating Rules for Voice VLANs
?
You must statically configure voice VLANs. GVRP and dynamic VLANs do not support voice VLAN operation.
?
Configure all ports in a voice VLAN as tagged members of the VLAN. This ensures retention of the QoS (Quality of Service) priority included in voice VLAN traffic moving through your network.
?
If a telephone connected to a voice VLAN includes a data port used for connecting other networked devices (such as PCs) to the network, then you must configure the port as a tagged member of the voice VLAN and a tagged or untagged member of the data VLAN you want the other networked device to use.
2-60
Static Virtual LANs (VLANs)
Special VLAN Types
Components of Voice VLAN Operation
? Voice VLAN(s): Configure one or more voice VLANs on the switch. Some reasons for having multiple voice VLANs include:
•
Employing telephones with different VLAN requirements
•
Better control of bandwidth usage
•
Segregating telephone groups used for different, exclusive purposes
Where multiple voice VLANs exist on the switch, you can use routing to
communicate between telephones on different voice VLANs. .
? Tagged/Untagged VLAN Membership: If the appliances using a voice VLAN transmit tagged VLAN packets, then configure the member ports as tagged members of the VLAN. Otherwise, configure the ports as untagged members.
Voice VLAN QoS Prioritizing (Optional)
Without configuring the switch to prioritize voice VLAN traffic, one of the following conditions applies:
?
If the ports in a voice VLAN are not tagged members, then the switch forwards all traffic on that VLAN at “normal” priority.
?
If the ports in a voice VLAN are tagged members, then the switch forwards all traffic on that VLAN at whatever priority the traffic has when received inbound on the switch.
Using the switch’s QoS VLAN-ID (VID) Priority option, you can change the priority of voice VLAN traffic moving through the switch. If all port memberships on the voice VLAN are tagged, the priority level you set for voice VLAN traffic is carried to the next device. With all ports on the voice VLAN configured as tagged members, you can enforce a QoS priority policy moving through the switch and through your network. To set a priority on a voice VLAN, use the following command:
Syntax: vlan < vid > qos priority < 0 - 7 >
The qos priority default setting is 0 (normal), with 1 as the lowest priority and 7 as the highest priority.
For example, if you configured a voice VLAN with a VID of 10, and wanted the highest priority for all traffic on this VLAN, you would execute the following command:
ProCurve(config) # vlan 10 qos priority 7ProCurve (config) # write memory
2-61
Static Virtual LANs (VLANs)
Effect of VLANs on Other Switch Features
Note that you also have the option of resetting the DSCP (DiffServe Code-point) on tagged voice VLAN traffic moving through the switch. For more on this and other QoS topics, refer to the chapter titled “Quality of Service (QoS): Managing Bandwidth More Effectively” in this guide.
The voice tag is just that, a QoS tagging that informs the switch to take on the settings of equipment that originally marked the QoS packet. So for example, using a Mitel system, the handset tags the traffic when you make a call, when the traffic hits the switch, instead of having to specifically mark the traffic again to the same or even higher preference, the switch reads what those existing markings are and uses those same markings to pass it on upstream. Think of it as an "auto QoS" setting, so it will take on the QoS settings of whatever initiated the packet stream.
I know some phone systems that HP has been tested with take advantage of this setting like Mitel and, I think, ShoreTel, while others like Avaya, still prefer QoS to be well defined on the switch.
In regards to CDP, HP dropped support in their IOS for CDP several years back on their Procurve switches and like mentioned, they support the standard LLDP. I cannot answer for the switches they just recently acquired from 3COM, etc... It was just recently within the past year that Cisco decided to add LLDP to their phones...go figure, Cisco having a standards based protocol (although they still hang on to their proprietary CDP).
That's the bit I've asked my local Procurve tech about, Cajun - the implication seems to be that if you do not set the "voice" option, they will not honour the QoS markings in the frames coming from the phones.
This can't be correct, or QoS wouldn't work for non-voice applications (?).
I've never used Procurve switches for VoIP, so I've never had to delve into this before, but I'm going to get to the bottom of it.
I want to know what, specifically, the switch does at layer2 and layer3 when this "voice" option is set on a VLAN.
I remember HP removed CDP from their firmware about halfway through 2005, but on the current 3500s and 5400s v14 and v15 firmware CDP is back in there and on by default (as well as LLDP).
On the new HP rebadged 3COM stuff, I don't think we have CDP:
[CR-G181-SAT233]lldp ?
compliance Enable compliance with another link layer discovery protocol
enable Enable capability
fast-count The fast-start times of transmitting frames
hold-multiplier Hold multiplicator for TTL
timer Timer of LLDP
[CR-G181-SAT233]cdp ?
^
% Unrecognized command found at '^' position.
Ok, let me be more technically specific... the HP Procurve switches use LLDP for dicovery, but there is a extension of LLDP called LLDP-MED which is used for phone and video device discovery. The "voice" command technically enables LLDP-MED which has the effect of automatically allowing QoS policies to run by using the endpoints markings instead of having to manually define those policies on the interfaces of the switch. Vendors like Avaya, Mitel, ShoreTel, and some others follow usage of this protocol as mentioned.
I stand corrected on the CDP, I don't use it as I have no Cisco equipment except for two routers and have not had the need for CDP for quite some time. I knew they removed it a few years ago, but failed to realize they added it back as mentioned. Thanks for the info.
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