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FosteringInteroperability withVoIP Solutions via HP ProCurveNetworking
Performance evaluation of the HP ProCurve Networking AdaptiveEDGE Architecture and its ability to'interoperate' with leading VoIP solutions suppliers
A white papercommissioned by
Hewlett-Packard Co.
Document #204113
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This document was authored by:
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Charles Bruno,Executive EditorThe Tolly Group
Kevin Tolly,President/CEOThe Tolly Group
1 A Blueprint for VoIP Infrastructure 2 Gaining a Competitive EDGE 3 Bandwidth control services 4 Open approach to standards 6 Fostering Interoperability for VoIP 6 Cisco AVVID traffic across HP ProCurve 7 AVVID/HP ProCurve Switch 2650-PWR edge scenario 7 AVVID/HP ProCurve Switch 4104gl edge scenario 8 AVVID/HP ProCurve Switch 5304xl edge scenario 8 VoIP call quality using Mitel 3300-ICP traffic across HP ProCurve9 Mitel/HP ProCurve Switch 2650-PWR edge scenario 9 Mitel/ProCurve 4104gl edge scenario 10 Mitel/HP ProCurve Switch 5304xl edge scenario 10 VoIP call quality using 3Com NBX-100 traffic across HP ProCurve11 NBX-100/HP ProCurve Switch 2650-PWR edge scenario 11 NBX-100/HP ProCurve Switch 4104gl edge scenario 11 NBX-100/HP ProCurve Switch 5304xl edge scenario 12 VoIP call quality using Avaya IP403 Office 12 VoIP call quality using NEC NeaxIPS 13 VoIP call quality using Nortel BCM200 14 Making Smart Purchase Decisions
©2004 The Tolly Group January 2004
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7 Figure 1. AVVID over HP ProCurve PSQM summary8 Figure 2. AVVID over HP ProCurve PESQ summary9 Figure 3. PSQM summary results for Mitel VoIP over HP ProCurve10 Figure 4. PESQ results for Mitel VoIP over HP ProCurve11 Figure 5. PSQM summary results for 3Com NBX VoIP over HP ProCurve12 Figure 7. PSQM summary results for Avaya, NEC and Nortel12 Figure 6. PESQ summary results for 3Com NBX VoIP over HP ProCurve13 Figure 8. PESQ summary results for Avaya, NEC and Nortel13 Figure 9. Latency results for Avaya, NEC and Nortel
Table of Contents
List of Figures
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1
A Blueprint for VoIP Infrastructure
Organizations intent on transitioning their physically separate voice and
data networks onto a single, shared transport infrastructure are seeking
an economical means to unite multiple platforms yet do so without
compromising the quality of either voice or data traffic.
Call it ironic, then, that the road to network convergence sometimes is
paved with architectural complexity that either intentionally walls off the
network to third-party equipment, or makes it extremely difficult to build
a heterogeneous converged network. The irony, of course, is that the
foundation of converged enterprise networks these days is IP – only the
most ubiquitous and open protocol in network use.
Yet, as enterprise network designers begin to shape their converged
networks, they sometimes are guided toward a homogeneous network
infrastructure that will "guarantee" acceptable call quality once latency-
sensitive voice is mixed with data applications. The oddity here is that IP
is IP; once voice data is converted into an IP packet, it travels across the
IP network just like any other data. There should be no issue with where
a VoIP packet originates since all IP should be equal.
Certainly, provisions must be made to recognize the latency-sensitive
voice over IP (VoIP) packets and treat them with special provisions for a
class of service above and beyond what some data types are afforded.
That's where quality of service (QoS) comes into play as a means to
supplement adequate bandwidth provisioning at the front end.
Unfortunately, some network infrastructure vendors blow QoS out of propor-
tion and make it overly complex. They reject the notion that adequate
bandwidth planning at the front-end design can help alleviate concerns
about VoIP call quality. Instead, they push the idea through resellers that
QoS is the sole means to guarantee VoIP call quality in enterprise networks.
HP ProCurve Networking, however, stands behind the belief that a
combination of careful upfront bandwidth provisioning, plus QoS as an
insurance policy for periods of link oversubscription, is an effective way
to ensure VoIP call quality.
That's why QoS is an important part of the HP ProCurve Networking
Adaptive EDGE Architecture™, the company's blueprint for deploying an
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Fostering Interoperability with VoIPSolutions via HP ProCurve Networking
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effective switching infrastructure that is capable of supporting VoIP traffic
in a secure manner.
HP commissioned The Tolly Group, in March 2003, and again in October
2003, to conduct a comprehensive, "hands-on" evaluation of the HP
ProCurve networking solution as implemented by the HP ProCurve
Networking Adaptive EDGE Architecture. The aim was two-fold:
First, testing sought to better understand the Adaptive EDGE Architecture
and the range of functionality it delivers to users.
Second, testing sought to demonstrate that HP ProCurve switches can
deliver VoIP traffic on an end-to-end basis without degrading call quality
– regardless of two variables: the level of congestion and the brand of IP
PBX products that attach to the VoIP switching infrastructure. The Tolly
Group constructed a microcosm of an enterprise IT converged network
using HP ProCurve products, and then measured and compared the call
quality of VoIP traffic from three IP telephony solutions (e.g. representa-
tive VoIP products from Mitel Corp., 3Com Corp. and Cisco Systems, Inc.)
to learn what impact, if any, the underlying ProCurve network has on
voice traffic. In the recent October tests, The Tolly Group evaluated three
additional VoIP solutions – from Avaya Networks, NEC and Nortel
Networks – as VoIP traffic originating from those brands of equipment
traverses an underlying HP switching infrastructure.
In the chapters that follow, readers will learn about the effectiveness of
HP ProCurve switch offerings at delivering VoIP traffic. Readers will see
that ProCurve is an efficient host infrastructure for VoIP traffic generated
by a variety of third-party products. And readers will learn that the
Adaptive EDGE Architecture provides an open, fertile infrastructure upon
which any VoIP traffic can flow across – regardless of what brand device
generates it.
Gaining a Competitive EDGE
HP ProCurve Networking designed its Adaptive EDGE Architecture to
provide intelligent services (such as security and QoS) at the edge of
the network thus providing greater control and functionality at the
edge. This means services like QoS, traffic conditioning and rate limiting
occur before traffic makes it onto the enterprise network core.
HP ProCurve took into account three factors in designing its Adaptive
EDGE Architecture that are influencing the design and evolution of
enterprise nets: the Internet, convergence and mobility.
Since the Internet has become such a force, it has provided enormous
access for outsiders to gain entry to enterprise-class data and services.
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HP evaluated ProCurve interoperabilitywith VoIP solutions from:
3ComAvayaCisco SystemsMitelNECNortel Networks
HP ProCurve's Adaptive EDGEArchitecture addresses three key market factors:
SecurityConvergenceMobility
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That means the network architecture must be able to grant that access,
at the network's edge, taking into account the proper level of access
and privileges afforded different "visitors."
Network convergence, or the unification of physically separate voice
and data networks into a single IP-based transport infrastructure,
means that any underlying switching infrastructure must support a broad
range of applications.
Finally, the emergence of mobility means that the network infrastructure
must stretch to accommodate wireless users, and still maintain the
security policies enforced on wired networks.
In essence, HP contends that these factors combine to create a need
for a flexible multi-service transport architecture where control and
functionality are deployed to the edges of the network. Control of
security and of bandwidth at the edge ensures that latency-sensitive
applications get the bandwidth they need, when they need it and
that other applications can yield to higher priority traffic.
One of the tenets of the Adaptive EDGE Architecture is that each of
the traffic types residing on converged networks – voice, video, storage,
interprocess communications and trusted (authenticated and encrypted)
traffic – requires different responses and behaviors that the network
adjust to and respond to accordingly. Delivering that right response
hinges largely on pushing authentication of the traffic type out to the
network edge where users can be identified and applications connect –
despite changes to the user's physical location.
The network edge, HP contends, is where traffic, applications and users
must be identified and decisions must be made on how traffic should be
handled. The edge is where security policies are enforced. Control to
the edge means that sufficient capabilities must be deployed in
ProCurve Layer 2/Layer 3 and Layer 4 switches.
Bandwidth control services
The HP ProCurve Networking Adaptive EDGE Architecture focuses
on a handful of strategic infrastructure services:
Traffic monitoring is employed to control bandwidth optimization
throughout the network grid.
Industry-standard virtual LAN (VLAN) security provides access
management on EDGE-enabled ports.
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HP ProCurve switches offer a weightedrandom fair queueing mechanism to limit delay and improve QoS byscheduling packets for bandwidthavailability.
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Standards-based traffic routing and Layer 2 mesh networking provides
multipath failover and load balancing for enhanced reliability. HP
ProCurve Layer 2 and Layer 3 switches can recognize priority tags and
tag non-prioritized traffic for end-to-end delivery across the network.
An extensive set of traffic prioritization features and Quality of Service
(QoS) functions enable various traffic types to co-reside peacefully
to ensure the delivery of voice and video traffic.
HP ProCurve switches offer a weighted fair queuing mechanism to
limit delay and improve QoS by scheduling packets for bandwidth
availability. This approach ensures that higher-priority traffic types,
like VoIP, video and network management data, get the bandwidth
they need when they need it and still permit other traffic types to
share the same physical link.
Port prioritization is another technique offered in the HP ProCurve
switch line that enables priority levels to be set for untagged packets
received on any port. Such a capability enables administrators to
assign a higher priority to certain ports – such as those that service
large amounts of VoIP traffic – to guarantee faster access to and
availability of bandwidth.
Beyond these traffic management services, ProCurve switches support
a variety of protocols used in traffic classification including: UDP/TCP
port, source port, VLAN, Ethernet, IP address, IP Type of Service bit, and
the IETF's Differentiated Services (DiffServ) policies for IP prioritization.
In addition to distributed control at the edge, central command of the
network edge devices facilitates user security and application policies.
In the Adaptive EDGE Architecture, these services combine to ensure
that latency is kept to a minimum and to guard against packet loss –
two factors that otherwise could adversely impact the toll quality
of VoIP traffic.
In addition to the prioritization and QoS services, the Adaptive EDGE
Architecture also provides a foundation for security at the network's
edge – be it wired or wireless. Network designer's can make use of
port-based access control, media access control facilities and a
variety of other functions.
Open approach to standards
One of the basic themes of this white paper is to demonstrate how the
HP ProCurve switching line provides a fertile infrastructure for converged
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Traffic Classification Types Supportedby HP ProCurve:
UDP/TCPVLANEthernetIP addressType of Service bitDiffServe
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networks supporting voice, video and data. Paramount to HP's
approach with ProCurve is its support for a plethora of standards to
promote openness and interoperability. It is this very strategy that makes
ProCurve a viable platform for any number of VoIP solutions to utilize.
HP understands that an open standards-based approach to IP
networking is a key underpinning to providing an open switching
infrastructure for VoIP convergence. HP ProCurve's broad support for
standards begins with IP support, extends to support for the H.323
telephony standard and ranges into a number of other areas.
HP ProCurve also supports the IETF's Session Initiation Protocol, which
is emerging as a major factor in enterprise-class VoIP services.
Likewise, the IEEE 802.3af standard for Power over Ethernet is supported
on the HP ProCurve line – an important factor that ultimately plays
into system reliability.
By embracing standards such as these, and more, HP positions
ProCurve as an effective open platform for third-party VoIP solutions –
IP PBXs, gateways, etc – to use as a transport for voice traffic. HP's
pervasive standards support ensures third parties that ProCurve can
"interoperate" with other VoIP gear to carry IP traffic and ensure that
voice calls placed across the network deliver a level of call quality
excellence unsurpassed by other infrastructure providers. HP refers
to this as a "universal" infrastructure that can accommodate virtually
any industry-standard vendors' VoIP solution.
In Chapter 3, The Tolly Group examines HP ProCurve's capability to
support VoIP traffic generated by six different VoIP platforms: Cisco
AVVID traffic generated by a Cisco Call Manager, VoIP traffic gener-
ated by an older generation 3Com Corp. NBX-100 IP PBX and VoIP
calls handed off from a Mitel Corp. 3300-Integrated Communications
Platform (ICP). The 3Com NBX-100, Cisco AVVID and Mitel 3300-ICP
VoIP solutions originally were tested in May 2003. More recently, in
October 2003, The Tolly Group tested three more VoIP platforms for
their 'interoperability' with the HP ProCurve switching infrastructure:
Avaya IP403 Office, NEC NeaxIPS and a Nortel Networks BCM200.
Note as you examine Chapter 3, HP was not intent to demonstrate
that ProCurve can deliver VoIP traffic with just a single configuration
of access switch, aggregation switch and core switch. HP under-
stands that users often have different requirements at the access
level, and, consequently it tested three different access switches to
demonstrate the uniformity of call quality that HP ProCurve
Networking solutions deliver.
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By embracing standards, HP positionsProCurve as an open, viable platformfor third-party VoIP solutions.
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Fostering Interoperability for VoIP
HP ProCurve's switch line is based upon a QoS strategy that delivers band-
width provisioning, traffic control services and prioritization policies to man-
age traffic effectively and ensure that high-priority data types receive the
bandwidth they need, when they need it.
HP ProCurve's commitment to QoS in its switch product line, and in the
Adaptive EDGE Architecture, is the keystone to enabling third-party voice
solutions, such as IP PBX and VoIP gateways, to utilize HP ProCurve switch
fabrics effectively as an IP transport. HP's broad support for QoS mecha-
nisms assures third-party VoIP solution providers that they can overlay their
IP-based voice traffic on top of a switching fabric that will treat latency-
sensitive voice in the manner it deserves and needs.
In the sections that follow, The Tolly Group will chronicle six VoIP solutions:
Avaya IP403 Office, Cisco's AVVID/Call Manager, Mitel Corp.'s 3300-
Integrated Communications Platform, NEC NeaxIPS, Nortel Networks Business
Communication Manager 200 (BCM200) and 3Com Corp.'s NBX-100. All of
these offerings have been tested to determine the quality of VoIP when tra-
versing an HP switching infrastructure and the amount of latency produced.
Cisco's AVVID also was tested as it ran across a Cisco switching fabric and
3Com's NBX-100 was tested across a 3Com switching fabric.
Engineers tested the call quality of each of these systems supporting
calls placed across the HP ProCurve network between a pair of IP phones.
The goal here is to demonstrate that HP ProCurve and its QoS facilities
transport VoIP traffic with no adverse impact on call quality – regardless of
the VoIP solution employed.
Lastly, in the May 2003 version of this white paper, The Tolly Group reported
PSQM and PESQ call quality results. However, upon deeper analysis, we
have come to the conclusion that call quality is largely a factor of the
IP PBX or VoIP gateway that generates the traffic. What we seek to prove
in this white paper is the delta between the baseline call quality and
the toll quality when congestion is present and QoS kicks in. That percentage
delta is the true arbiter of the underlying switch fabric and its impact, or
lack thereof, on VoIP traffic.
Cisco AVVID traffic across HP ProCurve
If there ever was any question about whether Cisco AVVID VoIP traffic
can ride over an HP ProCurve switch fabric and still deliver the same
call quality as a Catalyst network, then Tolly Group testing will put
that to rest.
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Tests focused on passing AVVID VoIP traffic across a ProCurve switching
fabric. By contrast, Cisco's AVVID master plan for VoIP consists of a
Cisco Call Manager for the voice portion of the AVVID solution. Some
Cisco resellers contend that users must employ a Cisco Catalyst
switching infrastructure to obtain the QoS attributes and call quality
necessary for enterprise networks.
Tests measured call quality on an "ear-to-ear" basis from the access
(edge) switch level, through the aggregation point and into the
core where the call terminated at a locally attached IP phone.
AVVID/HP ProCurve Switch 2650-PWR edge scenario
In one scenario, engineers measured the call
quality of AVVID traffic traversing a network with
an HP ProCurve Switch 2650-PWR (a stackable
50-port edge device), an HP ProCurve Switch
5308xl and an HP ProCurve Routing Switch
9308m at the core.
On the PSQM side, there was virtually no differ-
ence between the baseline score and the
with QoS tests, highlighting that the HP ProCurve
infrastructure had no impact on VoIP call quality.
(See Figure 1.)
PESQ test scores bear out same result. Test results
show that there was less than a 1% reduction in toll
quality of baseline tests versus tests conducted with
congestion and QoS active. Again, this demon-
strates that HP ProCurve has no adverse affect on
toll quality (See Figure 2). Likewise, one-way delay
was a low 76 ms. for the baseline and 71 ms. during
the congestion scenario.
AVVID/HP ProCurve Switch 4104gl edge scenario
Next, we re-ran the voice quality tests, this time swapping out the
HP ProCurve Switch 2650-PWR and replacing it with an HP
ProCurve Switch 4104gl, a four-slot modular chassis switch. It oper-
ated alongside the HP ProCurve Switch 5308xl and an HP ProCurve
Routing Switch 9308m at the core to support AVVID VoIP traffic.
On the PSQM side, here again the HP ProCurve delivered voice traffic,
actually improving toll-quality by less than 1% during the test of con-
gestion with active QoS. (See Figure 1.) This establishes a pattern of
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Performance Delta of PSQM ScoresAVVID over ProCurve Scenario
Baseline vs. Congestion QoS Test(Higher bars are better)
0%
+1%
+2%
0
0.5
1
1.5
2
2.5
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crea
se/d
ecre
ase
HP2650-PWR HP4104gl HP5304xl
Figure 1. AVVID over HP ProCurve PSQM summary
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voice quality consistency, regardless of which access
switch is used in the underlying HP ProCurve fabric.
PESQ scores again backed up the PSQM results. In
tests, the HP ProCurve Switch 4104gl scenario
yielded an improvement of about 1% over base-
line results when the congestion with QoS test was
run. (See Figure 2.)
One-way delay was just 75 ms. for the baseline
and 72 ms. during the congestion scenario.
AVVID/HP ProCurve Switch 5304xledge scenario
Engineers inserted the HP ProCurve Switch 5304xl as
the edge switch; this device is a four-slot Layer 2/3/4
chassis switch that can be used either at the edge
or as an aggregation point. It operated alongside
the HP ProCurve Switch 5308xl aggregation switch
and an HP ProCurve Routing Switch 9308m as a
core switch to support AVVID VoIP traffic.
Here there was a 2% performance improvement between the base-
line and the PSQM congestion with QoS test – however, such a small
delta indicates there a subtle improvement, if at all perceptible, that
the HP ProCurve switch fabric has on the voice traffic.
Likewise, there was less than a 1% decline in voice quality between the
baseline and congestion with QoS tests when the HP ProCurve Switch
5304xl was measured with PESQ. The baseline yielded a PESQ score of
4.03 and the congestion with QoS test resulted in a score of 4.00 – both
well above the PESQ threshold of 3.8 for excellent toll quality and both
providing a delta that shows consistency of toll quality provided by the
underlying HP ProCurve infrastructure.
One-way delay was fine, at 67 ms. for the baseline and 65 ms.
for the congestion test with QoS.
VoIP call quality using Mitel 3300-ICP traffic across HP ProCurve
HP ProCurve Networking partners its own data networking expertise
with Mitel, a premiere VoIP supplier. Certainly that message rang in
loud and clear during call quality testing.
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Performance Delta of PESQ ScoresAVVID over ProCurve Scenario
Baseline vs. Congestion QoS Test(Higher bars are better)
-1%
+1%
-1%-1.5
-1
-0.5
0
0.5
1
1.5
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ase
HP2650-PWR HP4104gl HP5304xl
Figure 2. AVVID over HP ProCurve PESQ summary
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Here we measured call quality and demonstrated the close connec-
tivity between the Mitel 3300-ICP and the ProCurve switching infra-
structure. Engineers subjected the Mitel 3300-ICP to the same switch
scenarios as tested with the Cisco AVVID traffic.
Mitel/HP ProCurve Switch 2650-PWR edge scenario
In this scenario, we measured the call quality of Mitel 3300-ICP
traffic traversing a network with an HP ProCurve Switch 2650-PWR
at the edge (a stackable 50-port device), an HP
ProCurve Switch 5308xl aggregation switch and
an HP ProCurve Routing Switch 9308m core
switch.
In PSQM tests, the Mitel call quality over the HP
ProCurve fabric yielded a delta of almost -3.5%
between the baseline and the congestion with
QoS tests. (See Figure 3.) Such a small dip does
not result in noticeable impact on toll quality to
the human ear. This scenario yielded phenome-
nally high call quality that equates to a perform-
ance improvement of almost 100% versus the
Cisco AVVID traffic operating in the same switch
fabric.
The PESQ scores were fine also, indicating less
than a 1% delta in voice quality for the baseline
versus the congestion with QoS test for each of
the switches tested. (See Figure 4.)
One-way delay was satisfactory, with 80 ms. for
the baseline and 94.5 ms for the congestion with
QoS test – well within standard limits.
Mitel/ProCurve 4104gl edge scenario
We re-ran the voice quality tests, this time swapping out the HP
ProCurve 2650-PWR and replacing it with an HP ProCurve 4104gl, a
four-slot modular chassis switch. It operated alongside the HP
ProCurve 5308xl aggregation switch and a HP ProCurve 9308m core
switch to support Mitel 3300-ICP VoIP traffic.
Again, PSQM scores indicated excellent voice quality with a base-
line score of 0.56 and congestion with QoS score of 0.58 - less than
a 4% delta in performance but one that would be imperceptible
since the toll quality is still excellent.
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Performance Delta of PSQM ScoresMitel VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(Smaller % decrease is better)
-4% -4%
-12%1
-14
-12
-10
-8
-6
-4
-2
0
Perc
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ase
HP2650-PWR HP4104gl HP5304xl
Figure 3. PSQM summary results for Mitel VoIP over HP ProCurve
1 Note: The call quality measured during the baseline test and the QoS test representextremely high PSQM call quality score of 0.62 in the ProCurve 5304 scenario. Toll quality is considered any score less 1.29.
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(Any score less than 1.29 is considered excellent
toll quality.) Here again, this shows consistency of
call quality, regardless of the access switch type
in the infrastructure.
PESQ scores also indicated excellent voice quality,
with a delta of less than 1% between the baseline
and QoS test, further indicating that the ProCurve
switching infrastructure has no adverse impact on
call quality.
One-way delay was extremely low, with 58 ms. for
the baseline and 83 ms for the congestion with
QoS test.
Mitel/HP ProCurve Switch 5304xl edgescenario
Engineers inserted the HP ProCurve Switch 5304xl
as the edge switch; this device is a four-slot Layer
2/3/4 chassis switch that can be used either at the
edge or as an aggregation point. It operated
alongside the HP ProCurve 5308xl aggregation switch and an HP
ProCurve 9308m core switch to support Mitel 3300-ICP VoIP traffic.
In the PSQM baseline tests, the VoIP solution/switch fabric yielded a
score of 0.55 and a score of 0.62 in the congestion with QoS test – a
12% performance difference but still well within the 'excellent toll
quality' range. Once more, this demonstrates call quality consistency,
regardless of changes to the underlying switch infrastructure. For PESQ
tests, the performance delta was less than 1%, meaning there is no
perceptible impact on call quality by the HP ProCurve switching fabric.
One-way delay was 67 ms. for the baseline and 65 ms. for the con-
gestion with QoS test.
VoIP call quality using 3Com NBX-100 traffic across HP ProCurve
In addition to demonstrating the effectiveness of using an HP
ProCurve switching fabric to handle VoIP traffic on AVVID and Mitel
VoIP solutions, The Tolly Group also measured the 3Com NBX-100. The
NBX-100 IP PBX is an older generation IP PBX.
Engineers subjected the NBX-100 to the same switch scenarios as
with the Cisco AVVID and the Mitel-generated VoIP traffic.
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Performance Delta of PESQ ScoresMitel VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(lower bars are better)
-0.2%
-0.7%
-0.2%
-0.8
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
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HP2650-PWR HP4104gl HP5304xl
Figure 4. PESQ results for Mitel VoIP over HP ProCurve
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NBX-100/HP ProCurve Switch 2650-PWR edge scenario
In one scenario, engineers measured the quality of the 3Com NBX-100
traffic traversing a network with an HP ProCurve 2650-PWR edge switch
(a stackable 50-port device), an HP ProCurve 5308xl aggregation
switch and an HP ProCurve 9308m core switch.
In PSQM tests, the baseline yielded a score of 1.05
and the congestion with QoS test yielded a score of
1.02. Those call quality scores, again, are consistent
with the AVVID scores and represent toll quality
voice. The performance delta shows a 3% improve-
ment from the baseline to the congestion with QoS
test. (See Figure 5.) Again, the HP ProCurve switch
fabric does not adversely impact voice quality.
On the PESQ side, there was virtually no percepti-
ble difference between the baseline and conges-
tion with QoS tests. (See Figure 6.)
One-way delay was 79 ms. for the baseline and 78
ms. for the congestion with QoS test.
NBX-100/HP ProCurve Switch 4104gledge scenario
We re-ran the voice quality tests, this time swap-
ping out the HP ProCurve Switch 2650-PWR and
replacing it with an HP ProCurve Switch 4104gl, a
four-slot modular chassis switch. It operated
alongside the HP ProCurve 5308xl aggregation
switch and an HP ProCurve 9308m core switch to support NBX-100
VoIP traffic.
In PSQM tests, there was barely a 1% performance gain from the
baseline to the congestion with QoS test, indicating the HP ProCurve
network does not negatively impact VoIP. (See Figure 5.)
The PESQ scores showed virtually no change between the scores
for the baseline and the congestion with QoS tests. (See Figure 6.)
One-way delay was 83 ms. for the baseline and 80 ms. for the
congestion with QoS test.
NBX-100/HP ProCurve Switch 5304xl edge scenario
Engineers inserted the HP ProCurve 5304xl as the edge switch; this
device is a four-slot Layer 2/3/4 chassis switch that can be used
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Performance Delta of PSQM Scores3Com NBX VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(Higher bars are better)
+3%
-1%
+1%
-1.5
-1
-0.50
0.5
1
1.5
22.5
3
3.5
Perc
enta
gein
crea
se/d
ecre
ase
HP2650-PWR HP4104gl HP5304xl
Figure 5. PSQM summary results for 3Com NBX VoIP over HP ProCurve
WHITE PAPER:Fostering Interoperability with VoIP Solutions via
HP ProCurve Networking
©2004 The Tolly Group January 200412
either at the edge or as an aggregation point. It
operated alongside the HP ProCurve 5308xl aggre-
gation switch and an HP ProCurve 9308m core
switch to support NBX-100 VoIP traffic.
PSQM test results mirrored the Cisco AVVID call
quality with a score of 1.01 for the baseline and
1.02 for the congestion with QoS test – basically
less than a 1% performance change. (See Figure
5.) PESQ scores, likewise, showed barely a 1%
change in call quality. (See Figure 6.) Again, the
message is that HP ProCurve does not adversely
impact the call quality of VoIP traffic riding over
the switching infrastructure.
One-way delay was 79 ms for the baseline and 82
ms for the congestion with QoS test.
VoIP call quality using Avaya
IP403 Office
In this scenario, Tolly Group engineers measured
Avaya IP403 Office VoIP traffic traversing a net-
work with an HP ProCurve 2650-PWR edge switch
(a stackable 50-port device), an HP ProCurve
5308xl aggregation switch and a ProCurve 9308
core switch.
In PSQM tests, the difference between the PSQM
baseline score and the congestion with QoS
score represents a 1% drop in toll quality, which
likely would be imperceptible to users. (See Figure
7.) This is the same performance delta as
observed in the PESQ tests. Again, there is no evi-
dence that the ProCurve switching fabric has any
deleterious effect on VoIP call quality.
One-way delay was 117 ms. for the baseline and
131 ms. for the congestion with QoS test.
VoIP call quality using NEC NeaxIPS
Tolly Group engineers measured the quality of
NEC NeaxIPS VoIP traffic traversing a network with
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Performance Delta of PESQ Scores3Com NBX VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(Higher bars are better)
+1%
0%
-1%-1.5
-1
-0.5
0
0.5
1
1.5
Perc
enta
gein
crea
se/d
ecre
ase
HP2650-PWR HP4104gl HP5304xl
Figure 6. PESQ summary results for 3Com NBX VoIP over HP ProCurve
Performance Delta of PSQM ScoresAvaya/NEC/Nortel VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(Positive bars are better)
-1%
0%
-1%
-2.5
-2
-1.5
-1
-0.5
0
Perc
enta
gein
crea
se/d
ecre
ase
Avaya IP 403 NEC NeaxIPS Nortel BCM200
Figure 7. PSQM summary results for Avaya, NEC and Nortel
WHITE PAPER:Fostering Interoperability with VoIP Solutions via
HP ProCurve Networking
©2004 The Tolly Group January 200413
an HP ProCurve Switch 2650-PWR (a stackable
50-port edge device), an HP ProCurve 5308xl
aggregation switch and an HP ProCurve 9308m
core switch.
In PSQM tests, there was no difference in quality
between the baseline and QoS test scores.
(See Figure 7.)
In PESQ tests, the NEC NeaxIPS yielded a 1%
performance hike when comparing the toll
quality of the baseline and QoS tests. Again, such
a delta would be imperceptible to business users
and indicates there is no adverse effect of the
HP ProCurve switch fabric on the VoIP traffic.
(See Figure 8.)
One-way delay was 73 ms. for the baseline and
75 ms. for the congestion with QoS test.
VoIP call quality using Nortel BCM200
In this scenario, we measured the quality of Nortel BCM200 VoIP traffic
traversing a network with an HP ProCurve Switch 2650-PWR (a stack-
able 50-port edge device), an HP ProCurve 5308xl aggregation
switch and an HP ProCurve 9308m core switch.
In PSQM tests, the BCM200 call
quality over the HP ProCurve fabric
dropped by 1% between the
baseline and QoS tests; again this
delta is too small to have a per-
ceptible impact on calling parties.
(See Figure 7.)
By contrast, the PESQ scores show
that call quality increases from the
baseline to the QoS test by 3%.
(See Figure 8.)
One-way delay was satisfactory,
with 59 ms. for the baseline and
69 ms for the congestion with QoS
test – well within standard limits.
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Performance Delta of PESQ ScoresAvaya/NEC/Nortel VoIP over ProCurve Scenario
Baseline vs. Congestion QoS Test(Higher bars are better)
+1% +1%
+3%
0
0.5
1
1.5
2
2.5
3
3.5
Perc
enta
gein
crea
se/d
ecre
ase
Avaya IP 403 NEC NeaxIPS Nortel BCM200
Figure 8. PESQ summary results for Avaya, NEC and Nortel
One-Way Delayas reported by Agilent VQT
(Lower bars are better)
117
7359
131
75 69
0
20
40
60
80
100
120
140
Avaya IP403 Office NEC NeaxIPS Nortel BCM200
VoIP gatekeeper utilized
One
-way
del
ay in
m
illis
econ
ds
Baseline Congestion with QoS
Figure 9. Latency results for Avaya, NEC and Nortel
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HP ProCurve Networking
©2004 The Tolly Group January 200414
Making Smart Purchase Decisions
Users embarking upon a VoIP deployment have the option of installing a
solution from a one-stop shopping supplier, or adopting a best-of-breed
approach to VoIP. The Tolly Group advocates the latter approach.
Clearly, testing demonstrates that the HP ProCurve product line delivers a
stable IP switching infrastructure over which a variety of VoIP gateway
traffic can run unencumbered. Moreover, tests of congestion with QoS
show that ProCurve has the type of facilities necessary to ensure that
VoIP traffic receives preferential treatment – with little to no impact on
voice quality.
In test after test, with six different brand VoIP solutions, HP ProCurve
delivered consistent call quality and, equally important, low delay that
otherwise could imperil the quality of voice traffic. Certainly, HP ProCurve
has delivered a level of call quality equal to or better than other IP
switching fabrics tested by The Tolly Group.
But best-of-breed extends well beyond performance and call quality. It
factors in cost of ownership. In many instances, purchase decisions come
down to a price/performance issue. Here, HP historically has had a
compelling story to tell.
An August 2002 Tolly Group Test Summary commissioned by HP compared
the HP ProCurve Switch 5308xl versus a Cisco Catalyst 4006 on a
performance and cost-of-ownership basis (Test Summary document
202153 at www.tolly.com). From a performance standpoint, the HP
ProCurve switch delivered 100% of wire-speed Layer 2 throughput with
Gigabit Ethernet uplinks compared to just 25% from the Catalyst device
in the same scenario. Moreover, the HP ProCurve offered 20% less laten-
cy, which is important to latency-sensitive
applications like VoIP.
On the cost-of-ownership front, The Tolly Group found that the HP
ProCurve switch offered four times better the price/performance at less
than half the cost of the Catalyst device in a Fast Ethernet configuration
and about a fourth of the cost of the Cisco product in a 32-port Gigabit
Ethernet configuration. Moreover, HP ProCurve does not require an
extra-cost support contract, whereas the Catalyst required a $1,520
annual service/support contract.
Further, a November 2001 Test Summary on the HP ProCurve Switch
4108gl versus the Cisco Catalyst 4006 showed that the HP device posted
a cost-per-gigabit of throughput of $1,417 versus $9,261 in the Catalyst's
most expensive Gigabit Ethernet scenario tested (Test Summary
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WHITE PAPER:Fostering Interoperability with VoIP Solutions via
HP ProCurve Networking
©2004 The Tolly Group January 200415
document 201138 at www.tolly.com). Still, the HP ProCurve proved that its
cost-per-gigabit comes in anywhere between two to 12 times less than
the Cisco switch.
That's a compelling argument in favor of HP ProCurve as the underlying
network transport for a converged voice/data network.
Factor in HP's commitment to standards such as the ITU's 802.1p/Q, H.323
and others and users have an open communications platform capable
of accommodating VoIP traffic from literally any IP telephony vendor.
Tests prove that HP ProCurve Networking delivers able voice quality for
several representative VoIP IP PBX suppliers.
The fact that ProCurve provides an effective industry-standard solution
at an affordable price means that users can build their networks
affordably over time with a choice of solutions and can adapt to future
applications. In effect, clients get more out of technology to reduce
the initial cost of ownership and provide a better return on IT infrastructure.
It all boils down to one simple fact: HP ProCurve Networking delivers
excellent call quality for enterprise network users, and it does so while
providing an extremely competitive cost-of-ownership. Users will be
hard-pressed to find a better combination.
###
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©2004 The Tolly Group January 2004
The Tolly Group, Inc.3701 FAU Blvd. Suite 100
Boca Raton, FL 33431Phone: 561.391.5610
Fax: 561.391.5810http://www.tolly.com
WHITE PAPER:Fostering Interoperability with VoIP Solutions via
HP ProCurve Networking
16
Information technology is an area of rapid growth and constant change. The Tolly Group conductsengineering-caliber testing in an effort to provide the internetworking industry with valuable infor-mation on current products and technology. While great care is taken to assure utmost accuracy,mistakes can occur. In no event shall The Tolly Group be liable for damages of any kind includingdirect, indirect, special, incidental, and consequential damages which may result from the use ofinformation contained in this document. All trademarks are the property of their respective owners.
The Tolly Group doc. 204113 rev. clk 12 Jan 2004
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