Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > VOIP > Softphone QoS

Reply
Thread Tools

Softphone QoS

 
 
Arnold Ligtvoet
Guest
Posts: n/a
 
      10-09-2003
Hi,
I'm working on a project to implement Cisco CM in a corporate network.
The network itself is fine (100Mbit, switched) and based on Cisco
switches. The problem is that the customer wants to use only softphones
and does not have a CAT6500.

I'm having trouble separating 'normal' data traffic from VoIP traffic,
since the softphone does not set TOS fields or any other unique
qualification.

I was wondering if I could use a linux machine to insert the TOS into
packets based on content (ie. VoIP or any other data) or if there are
any other solutions that I can use.

The network uses a CAT2950-24 switch in conjunction with 2 clustered
MCS7825 CM servers.

TIA,
Arnold.

 
Reply With Quote
 
 
 
 
Plato
Guest
Posts: n/a
 
      10-09-2003
On Thu, 09 Oct 2003 11:00:18 +0200, Arnold Ligtvoet
<(E-Mail Removed)> wrote:

>Hi,
>I'm working on a project to implement Cisco CM in a corporate network.
>The network itself is fine (100Mbit, switched) and based on Cisco
>switches. The problem is that the customer wants to use only softphones
>and does not have a CAT6500.
>
>I'm having trouble separating 'normal' data traffic from VoIP traffic,
>since the softphone does not set TOS fields or any other unique
>qualification.
>
>I was wondering if I could use a linux machine to insert the TOS into
>packets based on content (ie. VoIP or any other data) or if there are
>any other solutions that I can use.
>
>The network uses a CAT2950-24 switch in conjunction with 2 clustered
>MCS7825 CM servers.
>
>TIA,
>Arnold.


you can prioritize traffic to the call manager via the destination IP
address. Unfortunately, no method that I'm aware of will allow you to
mark IP QoS for the call data traffic.
 
Reply With Quote
 
 
 
 
Arnold Ligtvoet
Guest
Posts: n/a
 
      10-09-2003
Plato wrote:

> On Thu, 09 Oct 2003 11:00:18 +0200, Arnold Ligtvoet
> <(E-Mail Removed)> wrote:
>
>
>>Hi,
>>I'm working on a project to implement Cisco CM in a corporate network.
>>The network itself is fine (100Mbit, switched) and based on Cisco
>>switches. The problem is that the customer wants to use only softphones
>>and does not have a CAT6500.
>>
>>I'm having trouble separating 'normal' data traffic from VoIP traffic,
>>since the softphone does not set TOS fields or any other unique
>>qualification.
>>
>>I was wondering if I could use a linux machine to insert the TOS into
>>packets based on content (ie. VoIP or any other data) or if there are
>>any other solutions that I can use.
>>
>>The network uses a CAT2950-24 switch in conjunction with 2 clustered
>>MCS7825 CM servers.
>>
>>TIA,
>>Arnold.

>
>
> you can prioritize traffic to the call manager via the destination IP
> address. Unfortunately, no method that I'm aware of will allow you to
> mark IP QoS for the call data traffic.


Yup, I thought of that option, also prioritized traffic to the gateway.
However the problem still remains on internal calls.

If was looking at solutions like a packetclassifier
(http://l7-filter.sourceforge.net/), but I can't see a way to implement
this on a switched network.

Arnold

 
Reply With Quote
 
Steve Blair
Guest
Posts: n/a
 
      10-09-2003

Arnold:

Some NIC cards include utilities that allow you to set
802.1p COS bits for specific applications. I realize
this may not fit your requirements but it is an option.
I know 3Com has such a utility for their NICs.

This an area I'm also interested in. We've been
pressuring softphone vendors to implement settable
802.1p COS within the soft client GUI, or it's
configuration file. Do Cisco have plans for such a
feature?

-Steve

Arnold Ligtvoet wrote:
> Hi,
> I'm working on a project to implement Cisco CM in a corporate network.
> The network itself is fine (100Mbit, switched) and based on Cisco
> switches. The problem is that the customer wants to use only softphones
> and does not have a CAT6500.
>
> I'm having trouble separating 'normal' data traffic from VoIP traffic,
> since the softphone does not set TOS fields or any other unique
> qualification.
>
> I was wondering if I could use a linux machine to insert the TOS into
> packets based on content (ie. VoIP or any other data) or if there are
> any other solutions that I can use.
>
> The network uses a CAT2950-24 switch in conjunction with 2 clustered
> MCS7825 CM servers.
>
> TIA,
> Arnold.
>


 
Reply With Quote
 
Pete Harris
Guest
Posts: n/a
 
      10-09-2003
Arnold Ligtvoet <(E-Mail Removed)> wrote

> I'm working on a project to implement Cisco CM in a corporate network.
> The network itself is fine (100Mbit, switched) and based on Cisco
> switches. The problem is that the customer wants to use only softphones
> and does not have a CAT6500.
>
> I'm having trouble separating 'normal' data traffic from VoIP traffic,
> since the softphone does not set TOS fields or any other unique
> qualification.


Are you sure your voice packets NEED to be handled differently? It
sounds like this network will rarely if ever saturate. On an
unsaturated network, QoS priority makes no difference, as all packets
are immediately forwarded.

Also, are you sure that the Cisco softphones don't set the ToS fields?
Why would they not set them? Is this a FUD tactic to get you to buy
more hard phones and extra routers?

In my experience, VoIP over LAN always works perfectly. VoIP over WAN,
especially VPN, is where the challenges are. If anybody has other
expeiences, I'd like to hear them.

- Pete
www.bg/qphone
 
Reply With Quote
 
shope
Guest
Posts: n/a
 
      10-09-2003
"Arnold Ligtvoet" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
> I'm working on a project to implement Cisco CM in a corporate network.
> The network itself is fine (100Mbit, switched) and based on Cisco
> switches. The problem is that the customer wants to use only softphones
> and does not have a CAT6500.
>
> I'm having trouble separating 'normal' data traffic from VoIP traffic,
> since the softphone does not set TOS fields or any other unique
> qualification.


Cant you use IP / UDP and socket numbers to identify the RTP packets for
classification?

I read some Cisco stuff on their IP Tel docs about IDing voice packets in
that way when they were showing suggested firewall filters for voice- try
the CM 3.x design guide info at
www.cisco.com/go/srnd

Not sure if you will be able to filter at that level with a 2950 though -
3550 needed?
>
> I was wondering if I could use a linux machine to insert the TOS into
> packets based on content (ie. VoIP or any other data) or if there are
> any other solutions that I can use.
>
> The network uses a CAT2950-24 switch in conjunction with 2 clustered
> MCS7825 CM servers.
>
> TIA,
> Arnold.

--
Regards

Stephen Hope - remove xx from email to reply


 
Reply With Quote
 
Arnold Ligtvoet
Guest
Posts: n/a
 
      10-09-2003
Pete Harris wrote:
> Arnold Ligtvoet <(E-Mail Removed)> wrote
>
>
>>I'm working on a project to implement Cisco CM in a corporate network.
>>The network itself is fine (100Mbit, switched) and based on Cisco
>>switches. The problem is that the customer wants to use only softphones
>>and does not have a CAT6500.
>>
>>I'm having trouble separating 'normal' data traffic from VoIP traffic,
>>since the softphone does not set TOS fields or any other unique
>>qualification.

>
>
> Are you sure your voice packets NEED to be handled differently? It
> sounds like this network will rarely if ever saturate. On an
> unsaturated network, QoS priority makes no difference, as all packets
> are immediately forwarded.
>
> Also, are you sure that the Cisco softphones don't set the ToS fields?
> Why would they not set them? Is this a FUD tactic to get you to buy
> more hard phones and extra routers?


Yep I'm pretty sure. I did another project a couple of months ago where
I ran into the exact same problem. Came in after the solution was sold
and the problem was there. Since the customer refused to invest in a
'better' switch I ended up installing hardphones. It would seem to me
that cisco could set ToS/CoS bits from an app, but they don't.

> In my experience, VoIP over LAN always works perfectly. VoIP over WAN,
> especially VPN, is where the challenges are. If anybody has other
> expeiences, I'd like to hear them.


I did some troubleshooting at a customer the other day. Setup was CM 3.3
with 2950 switches. Prioritized all traffic coming to and from the VG200
(voice to pstn was ok now). Internal voice calls were still very bad.
This customer was using 10 access databases which were opened from a
server and kept open all day

> - Pete
> www.bg/qphone


Arnold.

 
Reply With Quote
 
Arnold Ligtvoet
Guest
Posts: n/a
 
      10-09-2003
shope wrote:

> "Arnold Ligtvoet" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>
>>Hi,
>>I'm working on a project to implement Cisco CM in a corporate network.
>>The network itself is fine (100Mbit, switched) and based on Cisco
>>switches. The problem is that the customer wants to use only softphones
>>and does not have a CAT6500.
>>
>>I'm having trouble separating 'normal' data traffic from VoIP traffic,
>>since the softphone does not set TOS fields or any other unique
>>qualification.

>
>
> Cant you use IP / UDP and socket numbers to identify the RTP packets for
> classification?


IP is not that important (since all clients could potentially talk to
one another), UDP ports are negotiated in H.323 call setup or skinny in
Cisco's case. I could of course prioritize *all* UDP traffic, but I'm
not sure what implications that has.

> I read some Cisco stuff on their IP Tel docs about IDing voice packets in
> that way when they were showing suggested firewall filters for voice- try
> the CM 3.x design guide info at
> www.cisco.com/go/srnd
>
> Not sure if you will be able to filter at that level with a 2950 though -
> 3550 needed?


Yep you need a CAT3550 or CAT6000 to these kind of things. Both are a
*bit* more expensive than the 2950.

Arnold

 
Reply With Quote
 
Arnold Ligtvoet
Guest
Posts: n/a
 
      10-09-2003
Steve Blair wrote:

> Arnold Ligtvoet wrote:
>
>> Hi,
>> I'm working on a project to implement Cisco CM in a corporate network.
>> The network itself is fine (100Mbit, switched) and based on Cisco
>> switches. The problem is that the customer wants to use only
>> softphones and does not have a CAT6500.
>>
>> I'm having trouble separating 'normal' data traffic from VoIP traffic,
>> since the softphone does not set TOS fields or any other unique
>> qualification.
>>
>> I was wondering if I could use a linux machine to insert the TOS into
>> packets based on content (ie. VoIP or any other data) or if there are
>> any other solutions that I can use.
>>
>> The network uses a CAT2950-24 switch in conjunction with 2 clustered
>> MCS7825 CM servers.
>>
>> TIA,
>> Arnold.
>>

>
> Some NIC cards include utilities that allow you to set
> 802.1p COS bits for specific applications. I realize
> this may not fit your requirements but it is an option.
> I know 3Com has such a utility for their NICs.


Ok, I'll check the NIC's at this customer and see what the possibilities
are in this area.

> This an area I'm also interested in. We've been
> pressuring softphone vendors to implement settable
> 802.1p COS within the soft client GUI, or it's
> configuration file. Do Cisco have plans for such a
> feature?


I worked at a software company previously where we implemented a 'Cisco'
softpone on the basis of TAPI and wave redirect. The cisco wave drivers
take care of creating the packets and as far as we could determine there
is no way to set QoS parameters. The wavedrivers are also used by the
real Cisco softphone so my best guess would be that there is no support
for this.

I'm not aware of any plans that Cisco has in this area and never heard
it in any of there release schedules.

Arnold

 
Reply With Quote
 
Pete Harris
Guest
Posts: n/a
 
      10-10-2003
I wrote:

> > In my experience, VoIP over LAN always works perfectly. VoIP over WAN,
> > especially VPN, is where the challenges are. If anybody has other
> > experiences, I'd like to hear them.



> Arnold Ligtvoet <(E-Mail Removed)> replied:


> I did some troubleshooting at a customer the other day. Setup was CM 3.3
> with 2950 switches. Prioritized all traffic coming to and from the VG200
> (voice to pstn was ok now). Internal voice calls were still very bad.
> This customer was using 10 access databases which were opened from a
> server and kept open all day


What was wrong with the internal voice calls? Voice quality: Dropouts?
Latency? Distortion? ... or something else ?

How can the Access DBs cause enough traffic to saturate the network?
Are they serving up images or video? Is this or maybe something else
producing large numbers of high priority packets?

Is the backbone (that is, whatever's interconnecting the 2950s)
perhaps undersized ?

And how do you think the phones could talk to the PSTN gateway OK, but
not to each other? I suppose you must be doing some sort of
prioritization beyond TOS fields, and which is able to somehow favor
phone-to-gateway connections compared to phone-to-phone connections.

Something doesn't add up here...it would be great if you could fill in
some of the blanks.

- Pete
www.bg.com/qphone
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
[QOS] minimal hardware and IOS requirement for QOS dominix Cisco 2 02-06-2007 10:19 AM
Cisco Softphone Vlan Versus Preexisting Hardphone Voice Vlan Tennisman Cisco 1 09-23-2005 02:57 PM
Softphone LAN QoS CONFIG Tennisman Cisco 1 09-20-2005 03:55 PM
QOS for VOIP using 768k of FR / Auto QOS Andrew Albert Cisco 7 02-09-2005 07:42 PM
User Report SJPhone <softphone> with Vonage Softphone Pepperoni VOIP 0 12-20-2004 06:40 AM



Advertisments