1. The document discusses how Multi-Protocol Label Switching (MPLS) can improve Voice over Internet Protocol (VoIP) services by enabling traffic engineering and quality of service controls.
2. MPLS allows traffic to be forwarded at layer 2 for faster routing and makes it easier to manage networks for quality of service. This helps meet the low latency and jitter requirements of real-time VoIP traffic.
3. The document analyzes VoIP performance over an MPLS network connecting three branch offices using a network monitoring tool. It finds that while MPLS provides better connectivity than the public Internet, additional steps may be needed to deliver business-quality VoIP.
Mobile Transport Evolution with Unified MPLSCisco Canada
Mobile Service Providers are seeing unprecedented challenges in relation to their Transport architectures with the 3GPP evolution towards IP based Node Bs, LTE (Long Term Evolution) and LTE-Advanced. This presentation will initially discuss the network migration trends and factors that are changing how mobile networks are evolving. A description is provided on Unified MPLS and the current issues that need to be fixed and how this architecture addresses this. A more detailed analysis will then examine the options available for transporting GSM/2G, UMTS/3G traffic and IP/Ethernet Node B deployments and some of factors that need consideration like scalability, resiliency and security. Finally, there is a detailed description of the LTE/LTE - A evolution and the feature requirements made on the transport network. There will be detailed analysis of different LTE models and also some technical enhancements and proposals considered for the implementation of LTE in a Unified MPLS environment.
Our approach in this thesis is that, we have designed and built a National Carrier based core and edge network to simulate a real live scenario that spans the kingdom of Saudi Arabia. Some of the results in the thesis are presented against simulation time and some against network load.how to implement mpls on network
Mobile Transport Evolution with Unified MPLSCisco Canada
Mobile Service Providers are seeing unprecedented challenges in relation to their Transport architectures with the 3GPP evolution towards IP based Node Bs, LTE (Long Term Evolution) and LTE-Advanced. This presentation will initially discuss the network migration trends and factors that are changing how mobile networks are evolving. A description is provided on Unified MPLS and the current issues that need to be fixed and how this architecture addresses this. A more detailed analysis will then examine the options available for transporting GSM/2G, UMTS/3G traffic and IP/Ethernet Node B deployments and some of factors that need consideration like scalability, resiliency and security. Finally, there is a detailed description of the LTE/LTE - A evolution and the feature requirements made on the transport network. There will be detailed analysis of different LTE models and also some technical enhancements and proposals considered for the implementation of LTE in a Unified MPLS environment.
Our approach in this thesis is that, we have designed and built a National Carrier based core and edge network to simulate a real live scenario that spans the kingdom of Saudi Arabia. Some of the results in the thesis are presented against simulation time and some against network load.how to implement mpls on network
A Comparative Analysis of the Performance of VoIP Traffic with Different Type...ijcnac
The key QoS parameters for VoIP are delay, jitter and loss. In the Internet, VoIP requires
the underlying packet switched network to minimize the impact of these parameters. A
major contributing factor in this regard is traffic engineering carried out by scheduling
algorithms. This paper studies the behavior of different types of scheduling algorithms on
the delay, jitter and loss QoS parameters. The performance evaluation involves
identifying the scheduling algorithms which are most suitable for VoIP communications.
The result from the analysis also shows the impact of the QoS parameters on VoIP over
the Internet.
A Business Guide to MPLS IP VPN Migration: Five Critical FactorsXO Communications
Multi-Protocol Label Switching Internet Protocol Virtual Private Network, or MPLS IP VPN, refers to a VPN service enabled over a trusted provider’s private MPLS core backbone. It delivers the flexibility of an IP service with the essential service quality, performance, and security previously available only with legacy technologies. Other benefits include cost-effective security, any-to-any connectivity, Quality of Service, scalable bandwidth, and a platform for convergence.
MPLS VPN is a family of methods for using multiprotocol label switching (MPLS) to create virtual private networks (VPNs). MPLS VPN is a flexible method to transport and route several types of network traffic using an MPLS backbone.
MPLS-TP is subset of MPLS. It uses the same data plane as used by MPLS (Defined in RFC 3031 and RFC 3032). MPLS-TP has four major areas:-
1. Data Plane
2. Control Plane
3. O&M
4. Survivability
MPLS-TP has no control plane, the reason for this was that the recovery. If the dynamic control plane is used, in that case the convergence would depend on the dynamic protocol and providers cannot leverage the <50 ms failover time in that case. It uses the same QoS diffserv model except uniform model as used in MPLS.
The NGN Carrier Ethernet System: Technologies, Architecture and Deployment Mo...Cisco Canada
This presentation discusses market trends and its impact on Network infrastructure, Cisco carrier Ethernet Transport Architecture, Cisco carrier Ethernet portfolio and TCO Leadership.
Core Network Optimization: The Control Plane, Data Plane & BeyondRadisys Corporation
This presentation takes you through the challenges network operators are facing as they bring in more and more bandwidth-intensive applications to their network. There are ways to optimize the network from the RAN to the Core -- and improve QoS.
MPLS-TP control plane is beneficial. It brings significant automation and reduced OPEX. Management is provisioned and control plane NEs will co-exist in many networks. Many vendors are building NEs with both management and control plane provisioning.
A Comparative Analysis of the Performance of VoIP Traffic with Different Type...ijcnac
The key QoS parameters for VoIP are delay, jitter and loss. In the Internet, VoIP requires
the underlying packet switched network to minimize the impact of these parameters. A
major contributing factor in this regard is traffic engineering carried out by scheduling
algorithms. This paper studies the behavior of different types of scheduling algorithms on
the delay, jitter and loss QoS parameters. The performance evaluation involves
identifying the scheduling algorithms which are most suitable for VoIP communications.
The result from the analysis also shows the impact of the QoS parameters on VoIP over
the Internet.
A Business Guide to MPLS IP VPN Migration: Five Critical FactorsXO Communications
Multi-Protocol Label Switching Internet Protocol Virtual Private Network, or MPLS IP VPN, refers to a VPN service enabled over a trusted provider’s private MPLS core backbone. It delivers the flexibility of an IP service with the essential service quality, performance, and security previously available only with legacy technologies. Other benefits include cost-effective security, any-to-any connectivity, Quality of Service, scalable bandwidth, and a platform for convergence.
MPLS VPN is a family of methods for using multiprotocol label switching (MPLS) to create virtual private networks (VPNs). MPLS VPN is a flexible method to transport and route several types of network traffic using an MPLS backbone.
MPLS-TP is subset of MPLS. It uses the same data plane as used by MPLS (Defined in RFC 3031 and RFC 3032). MPLS-TP has four major areas:-
1. Data Plane
2. Control Plane
3. O&M
4. Survivability
MPLS-TP has no control plane, the reason for this was that the recovery. If the dynamic control plane is used, in that case the convergence would depend on the dynamic protocol and providers cannot leverage the <50 ms failover time in that case. It uses the same QoS diffserv model except uniform model as used in MPLS.
The NGN Carrier Ethernet System: Technologies, Architecture and Deployment Mo...Cisco Canada
This presentation discusses market trends and its impact on Network infrastructure, Cisco carrier Ethernet Transport Architecture, Cisco carrier Ethernet portfolio and TCO Leadership.
Core Network Optimization: The Control Plane, Data Plane & BeyondRadisys Corporation
This presentation takes you through the challenges network operators are facing as they bring in more and more bandwidth-intensive applications to their network. There are ways to optimize the network from the RAN to the Core -- and improve QoS.
MPLS-TP control plane is beneficial. It brings significant automation and reduced OPEX. Management is provisioned and control plane NEs will co-exist in many networks. Many vendors are building NEs with both management and control plane provisioning.
There is an actual interview in this project, but names of the company and the engineer and associated products and aquisitions were changed for legal protection purposes.
This is my Athcon 2013 slide set. I also demonstrated that attacking mobile applications via SIP Trust, scanning via SIP proxies and MITM fuzzing in Live Demo.
VoIP Wars: Destroying Jar Jar Lync (Unfiltered version)Fatih Ozavci
Enterprise companies are increasingly using Microsoft Lync 2010/2013 (a.k.a Skype for Business 2015) services as call centre, internal communication, cloud communication and video conference platform. These services are based on the VoIP and instant messaging protocols, and support multiple client types such as Microsoft Office 365, Microsoft Lync, Skype for Business, IP phones and teleconference devices. Also the official clients are available for mobile devices (e.g. Windows phone, Android and iOS), desktops (Mac, Linux and Windows) and web applications developed with .NET framework. Although the Microsoft Lync platform has been developed along with the new technologies, it still suffers from old VoIP, teleconference and platform issues.
Modern VoIP attacks can be used to attack Microsoft Lync environments to obtain unauthorised access to the infrastructure. Open MS Lync frontend and edge servers, insecure federation security design, lack of encryption, insufficient defence for VoIP attacks and insecure compatibility options may allow attackers to hijack enterprise communications. The enterprise users and employees are also the next generation targets for these attackers. They can attack client soft phones and handsets using the broken communication, invalid protocol options and malicious messaging content to compromise sensitive business assets. These attacks may lead to privacy violations, legal issues, call/toll fraud and intelligence collection.
Attack vectors and practical threats against the Microsoft Lync ecosystem will be presented with newly published vulnerabilities and Microsoft Lync testing modules of the Viproy VoIP kit developed by the speaker. This will be accompanied by live demonstrations against a test environment.
• A brief introduction to Microsoft Lync ecosystem
• Security requirements, design vulnerabilities and priorities
• Modern threats against commercial Microsoft Lync services
• Demonstration of new attack vectors against target test platform
The Art of VoIP Hacking - Defcon 23 WorkshopFatih Ozavci
VoIP attacks have evolved, and they are targeting Unified Communications (UC), commercial services, hosted environment and call centres using major vendor and protocol vulnerabilities. This workshop is designed to demonstrate these cutting edge VoIP attacks, and improve the VoIP skills of the incident response teams, penetration testers and network engineers. Signalling protocols are the centre of UC environments, but also susceptible to IP spoofing, trust issues, call spoofing, authentication bypass and invalid signalling flows. They can be hacked with legacy techniques, but a set of new attacks will be demonstrated in this workshop. This workshop includes basic attack types for UC infrastructure, advanced attacks to the SIP and Skinny protocol weaknesses, network infrastructure attacks, value added services analysis, Cdr/Log/Billing analysis and Viproy use to analyse signalling services using novel techniques. Also the well-known attacks to the network infrastructure will be combined with the current VoIP vulnerabilities to test the target workshop network. Attacking VoIP services requires limited knowledge today with the Viproy Penetration Testing Kit (written by Fatih). It has a dozen modules to test trust hacking issues, information collected from SIP and Skinny services, gaining unauthorised access, call redirection, call spoofing, brute-forcing VoIP accounts, Cisco CUCDM exploitation and debugging services using as MITM. Furthermore, Viproy provides these attack modules in the Metasploit Framework environment with full integration. The workshop contains live demonstration of practical VoIP attacks and usage of the Viproy modules.
In this hands-on workshop, attendees will learn about basic attack types for UC infrastructure, advanced attacks to the SIP protocol weaknesses, Cisco Skinny protocol hacking, hacking Cisco CUCDM and CUCM servers, network infrastructure attacks, value added services analysis, Cdr/Log/Billing analysis and Viproy VoIP pen-test kit to analyse VoIP services using novel techniques. New CDP, CUCDM and Cisco Skinny modules and techniques of Viproy will be demonstrated in the workshop as well.
Great slides about factors to consider when looking at migrating to MPLS. OnCall Telecom can help with all your migration and design concerns and handle your migration from order to implementation. Contact us today to discuss your organization's needs!
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Mpls vpn using vrf virtual routing and forwardingIJARIIT
Multi-Protocol Label Switching (MPLS) which was introduced by Internet Engineering Task Force (IETF) is
usually used in communication networks which started attracting all the internet service provider(ISP) networks with its
brilliant and excellent features that provide quality of services (QOS)and guarantees to traffic which carries data from one
network to another network directly through labels.
Virtual Private Network (VPN) is one of the highly useful MPLS applications which allow a service provider or a large enterprise
network to offer network Layer VPN services that guarantee and carries traffic securely and privately from customer’s one to
another through the service provider’s network. To support multiple customers that Customers Request for secure, reliable,
private and ultrafast connections over the internet MPLS VPN standards include the concept of a virtual router. This feature
called a VRF table. VRF or Virtual Routing and Forwarding technology that permit a router to have various routing table or
multiple VPN at the same time that they are located in the same router but they are independent and also the VRF feature in
VPN now allows different customers to use same IP addresses connected to the same ISP. A VRF exists inside a single MPLS
router and typically routers need at least one VRF for each customer attached to that particular router.
Performance of MPLS-based Virtual Private Networks and Classic Virtual Privat...TELKOMNIKA JOURNAL
Multiprotocol Label Switching (MPLS) is effective in managing and utilizing available network bandwidth. It has advanced security features and a lower time delay. The existing literature has covered the performance of MPLS-based networks in relation to conventional Internet Protocol (IP) networks. But, too few literatures exist on the performance of MPLS-based Virtual Private Networks (VPN) in relation to traditional VPN networks. In this paper, a comparison is made between the effectiveness of the MPLS-VPN network and a classic VPN network using simulation studies done on OPNET®. The performance metrics used to carry out the comparison include; End to End Delay, Voice Packet Sent/Received and Label Switched Path’s Traffic. The simulation study was carried out with Voice over Internet Protocol (VoIP) as the test bed. The result of the study showed that MPLS-based VPN networks outperform classic VPN networks.
PERFORMANCE EVALUATION OF OSPF AND RIP ON IPV4 & IPV6 TECHNOLOGY USING G.711 ...IJCNCJournal
Migration from IPv4 to IPv6 is still visibly slow, mainly because of the inherent cost involved in the implementation, hardware and software acquisition. However, there are many values IPv6 can bring to the
IP enabled environment as compared to IPv4, particularly for Voice Over Internet Protocol (VoIP) solutions. Many companies are drifting away from circuit based switching such as PSTN to packet based switching (VoIP) for collaboration. There are several factors determining the effective utilization and
quality of VoIP solutions. These include the choice of codec, echo control, packet loss, delay, delay variation (jitter), and the network topology. The network is basically the environment in which VoIP is deployed. State of art network design for VoIP technologies requires impeccable Interior Gateway routing
protocols that will reduce the convergence time of the network, in the event of a link failure. Choice of CODEC is also a main factor. Since most research work in this area did not consider a particular CODEC as a factor in determining performance, this paper will compare the behaviour of RIP and OSPF in IPv4
and IPv6 using G.711 CODEC with riverbed modeller17.5.
PERFORMANCE EVALUATION OF OSPF AND RIP ON IPV4 & IPV6 TECHNOLOGY USING G.711 ...IJCNCJournal
Migration from IPv4 to IPv6 is still visibly slow, mainly because of the inherent cost involved in the implementation, hardware and software acquisition. However, there are many values IPv6 can bring to the
IP enabled environment as compared to IPv4, particularly for Voice Over Internet Protocol (VoIP) solutions. Many companies are drifting away from circuit based switching such as PSTN to packet based switching (VoIP) for collaboration. There are several factors determining the effective utilization and
quality of VoIP solutions. These include the choice of codec, echo control, packet loss, delay, delay variation (jitter), and the network topology. The network is basically the environment in which VoIP is deployed. State of art network design for VoIP technologies requires impeccable Interior Gateway routing
protocols that will reduce the convergence time of the network, in the event of a link failure. Choice of CODEC is also a main factor. Since most research work in this area did not consider a particular CODEC as a factor in determining performance, this paper will compare the behaviour of RIP and OSPF in IPv4
and IPv6 using G.711 CODEC with riverbed modeller17.5.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
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Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Segment routing is a network technology focused on addressing the pain points of existing IP and Multiprotocol Label Switching (MPLS) networks in terms of simplicity, scale, and ease of operation. It’s a foundation for application engineered routing because it prepares the networks for new business models where applications can direct network behavior.
Segment routing seeks the right balance between distributed intelligence and centralized optimization and programming. It was built for the software-defined networking (SDN) era.
Segment routing enables enhanced packet forwarding behavior. It enables a network to transport unicast packets through a specific forwarding path, other than the normal shortest path that a packet usually takes. This capability benefits many use cases, and you can build those specific paths based on application requirements.
Segment routing uses the source routing paradigm. A node, usually a router but it can also be a switch, a trusted server, or a virtual forwarder running on a hypervisor, steers a packet through an ordered list of instructions, called segments. A segment can represent any instruction, topological or service-based. A segment can have a local semantic to a segment-routing node or global within a segment-routing network. Segment routing allows you to enforce a flow through any topological path and service chain while maintaining per-flow state only at the ingress node to the segment-routing network. To be aligned with modern IP networks, segment routing supports equal-cost multipath (ECMP) by design, and the forwarding within a segment-routing network uses all possible paths, when desired.
Performance Evaluation and Comparisons for IPv4&IPv6 using mpls Technologiesiosrjce
IOSR Journal of Electronics and Communication Engineering(IOSR-JECE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electronics and communication engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electronics and communication engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
1. North South University
ETE 605(2): IP Telephony
Project Report on
“VOIP on MPLS Network- Technology”
Submitted By
Md. Mazharul Islam Khan
ID# 063457056
Section: ETE-605(2)
Submitted To
Dr. Moshiour Rahman
Department of computer science and Engineering
North South University
Submission Date
15/04/2008
2. Contents
Page No.
Over View 3
Multiprotocol Level Switching (MPLS) 4
Why does MPLS matter for VOIP 6
How MPLS- Enables VOIP analysis 7
MPLS-QOS 7
What will MPLS do for VOIP Network 8
Voice Over MPLS / Diffserv Architechere 8
Challenges with VOIP 10
Conclution 10
3. Over view
Multi-protocol Label Switching (MPLS) has often been presented as a technology that
will help service providers deliver better performance and availability, including specific
benefits for demanding applications such as voice and video. In recent years, many
service providers have implemented MPLS technology in their core networks. Now, with
MPLS backbones in place, these carriers are offering MPLS-based services to enterprise
customers in support of voice over IP (VoIP) and video applications. The carriers are also
aggressively advertising the benefits of MPLS, claiming large improvements in
performance and availability when compared with using the public Internet.
Figure1: Basic Terminology of VOIP over MPLS Network
As shown in Figure 1: CNA was deployed at three of the customer’s branch offices.
These three offices are linked to parallel network fabrics by MPLS and Internet links at
T1 speeds. Through its monitoring and assessing mechanisms, CNA evaluated the quality
of voice communication between Branch Site 1 and Branch Site 2 and between Branch
Site 1 and Branch Site 3, 2004. The assessment was done using CNA configured to use
its Voice Application Model.
4. CNA Application Models follow a five-stage methodology, shown in Figure 2. From the
bottom, the five steps include:
1. The measurement of low-level network quantities such as latency, loss, and jitter for
each available path between locations.
2. The computation of transport delays from the raw scores or the impact on applications
in general, not taking specific application sensitivities into consideration.
3. The computation of application delay, specifically the mouth-to-ear delay that affects
VoIP. Note that high jitter would result in high application delay; similarly, sustained loss
results in lost speech and unintelligibility, leading to increased application delay
.4. The determination of an application quality metric, using a ranking from zero to five
stars, similar to movie ratings. For VoIP, this step effectively equates to a Mean Opinion
Score (MOS) calculation for the network: the larger the jitter or the greater the sustained
loss, the lower the MOS rating.
5. Finally, the time periods where the voice quality is determined to be unacceptable are
logged as “bad minutes” for that path.
Using this methodology, kept a cumulative count of all “bad minutes” observed on the
various MPLS and Internet path choices between the sites in question
Multi-protocol Label Switching (MPLS)
MPLS is a standards-approved technology for speeding up network traffic flow and
making it easier to manage. In addition to moving traffic faster overall, MPLS is flexible,
fast, cost efficient and allows for network segmentation. While MPLS technology has
been around for several years, businesses are now taking advantage of service provider
offerings and beginning their own corporate implementations. It's a good idea for
network architects and engineers to get a head start on the technology.
Multiprotocol Label Switching (MPLS) is a standards-approved technology for speeding
up network traffic flow and making it easier to manage. MPLS involves setting up a
specific path for a given sequence of packets, identified by a label put in each packet,
thus saving the time needed for a router to look up the address to the next node to forward
the packet to. MPLS is called multi protocol because it works with the Internet Protocol
(IP).
5. With reference to the standard model for a network (the Open Systems Interconnection,
or OSI model), MPLS allows most packets to be forwarded at the layer 2 (switching)
level rather than at the layer 3 (routing) level. In addition to moving traffic faster overall,
MPLS makes it easy to manage a network for quality of service (QoS). For these reasons,
the technique is expected to be readily adopted as networks begin to carry more and
different mixtures of traffic.
Figure 4: Multi protocol Level Switching Architecture
Like any significant business decision, a number of qualifying factors usually drive a
potential migration to MPLS. Several common reasons are:
• Converged services capabilities (voice, video, data).
• Any-to-any connectivity without the high cost of individual circuits.
• Advanced features for ingress and egress routing policies (load sharing, policy
routing).
• Secure flexibility of adding future businesses and partners (multiple VPN
support).
• Circuit consolidation (frame, T-X, ATM).
6. Why does MPLS matter for VOIP?
Multi-protocol label switching (MPLS) enables a common IP-based network to be used
for all network services and for multiple customers of a network operator. It allows IP
networks to carry voice, data and video traffic with differentiated service-level
performance parameters. MPLS also enables Voice over Internet protocol (VOIP)
services over IP networks, so that a network operator can offer private networking
services to multiple customers on a shared infrastructure. Although MPLS may be used
with non-IP networks, it is IP networking; and more specifically data, voice, video
services over IP networks; that makes MPLS an attractive and growing technology.
MPLS is used to ensure that all packets in a particular flow take the same route over a
backbone. Deployed by many telcos and service providers, MPLS can enable traffic
engineering to deliver the quality of service (QoS) required to support real-time voice and
video as well as service level agreements (SLAs) that guarantee bandwidth. An MPLS
network ingress element attaches labels to IP packets. This label instructs the routers and
switches in the network where to forward the packets based on reestablished IP routing
information. Label switched paths (LSP) are defined in routing tables, and are used to
send tagged packets on specific paths through the network. LSPs represent a new type of
virtual paths for segregating traffic in an IP network. MPLS has been applied to
implementing Virtual Private Networks, which is a key revenue generator for service
providers offering enterprise services.
engineering, and other techniques.
Figure 6: Call routing through MPLS
7. How MPLS-enabled VOIP analysis
The application of MPLS to IP networks adds a new challenge, but also a new
opportunity, for VoIP analysis and testing. The challenge is that VoIP traffic from
multiple different virtual networks and service class tiers are mixed on common physical
links. The opportunity is that MPLS provides a means to separate this traffic for targeted
analysis. It simply requires theright tools to do this.
The Network Analyzer comprises many MPLS capabilities that not only enable targeted
VoIP analysis over MPLS in specific domains (VPNs, LSPs, service tiers, etc), but also
enable analysis of underlying network layers including MPLS networks. When MPLS is
used in DiffServ architectures to provide prioritization for different services, diagnosing
performance problems can be significantly expedited by focusing the analysis domain on
specific LSPs. Using the Network Analyzer, one can see VoIP performance for all traffic
on a link, and for traffic in specific domains. These domains can be based on MPLS To
analyze in a specific domain, one first applies a capture filter for a specific LSP. A filter
can be applied for up to 6 values of labels in a label stack. One can further filter on
specific values for Class of Service (CoS). This enables one to then analyze VoIP for that
LSP, for targeted analysis
of performance for that service tier. One can view traffic performance, for both VoIP and
non-VoIP traffic, per LSP and CoS.
MPLS Quality of Service
QoS on an MPLS backbone is used to provide predictable, guaranteed performance
metrics required to transport real time and mission critical traffic. The providers have an
overall QoS architecture that is used to deliver a subset of QoS services to each customer.
Since MPLS also supports reservation of Layer 2 resources, MPLS can deliver finely
grained quality of service, much in the same manner as ATM and Frame Relay. DiffServ
can support up to 64 classes while the MPLS shim label supports up to 8 classes. --
MPLS Resource Center QoS for IP/MPLS Networks by Santiago Alvarez is a practical
guide that will help you facilitate the design, deployment, and operation of QoS using
Cisco IOS Software and Cisco IOS XR Software. The book provides a thorough
explanation of the technology behind MPLS QoS and related technologies, including the
different design options you can use to build an MPLS network with strict performance
requirements.
8. Figure 7: QoS Over MPLS Solutions
What will MPLS do for VOIP network?
MPLS based VOIP ( which offers exclusive and interconnectivity using Internet protocol
to computers or Local Area Networks across the PSTN) reduce customer-networking
complexity, costs and do away with the requirement of in-house WAN specialists.
Rather than setting up and managing individual point-to-point circuits between each
office using pair of Leased Lines, MPLS VOIP customers will need only one connection
from each office router to a Edge Router. MPLS VOIP is a technology that allows a
Service Provider to have complete control over parameters that are critical to offering its
customers service guarantees with regard to a high level of QOS e.g. bandwidth,
throughputs, latencies, jitters and availability. Many Company has tied up with various
Networking solution providers to provide end-to-end solution to its valued customers,
including Customer End (CE) routers and other networking components.
Voice over MPLS /Diffserv Architecture:
It is observed that the premium service (EF) of Diffserv is not enough alone to ensure the
quality of service. Some research results have shown the failure of EF PHB in meeting
the delay and jitter targets if an EF packet arrives on an output link on which a large BE
packet is already in the middle of being transmitted. Therefore it is important that some
type of prior reservation be made for transmission of real-time voice across a domain.
MPLS provides the mechanism that can be used to separate the BE traffic path from EF
and AF traffic path and to install explicitly routed LSP's (Label Switched Paths). We
have set up voice over MPLS/Diffserv using NS-2 simulator and its associated modules.
We are in the process of designing rules and specifications for an architecture to support
voice in an MPLS and Diffserv domain. These rules will dictate the formation of LSP's
9. carrying voice calls and aggregation of LSP's into virtual trunks across the domain. The
specifications are supposed to standardize the treatment of voice calls in the IP networks
and to make it easy to perform traffic engineering in a domain that deals with voice calls.
additional ports to the VOIP gateway and the voice data (in data form) is processed easily
by the PC. A Gateway interconnects the Voice source to the network through the local
exchange, forwards the voice to the destined subscriber across the Internet, and sends the
incoming calls to the corresponding extension via the PXB. VOIP delivers real-time and
two way synchronous voice traffic over the Internet or Intranet[2].
The IP telephony provides a number of benefits as compared to the Public Switched
Telephone Network (PSTN) such as: integration of voice, data and fax, sound grading,
video telephony, unified messaging, low-cost voice calls, real-time billing, remote
teleworking, enhanced teleconferencing, etc. It may face many technical challenges such
as: loss, delay, and jitter[3]. Internet telephony has caught the world's attention despite
the inferior quality for many of these connections. Many companies have introduced
products that improve and commercialize the technology. New protocols such as Diffserv
and MPLS are being introduced with additional features like QoS, reliability and traffic
engineering that improve the performance of voice transmission over the IP network.
Unlike data, VOIP is more sensitive to delay than loss, thus sufficient bandwidth must be
guaranteed to the voice application. Some protocols that decrease voice transmission
delay by giving high priority to the voice than data traffic have been introduced.
Resource reSerVation Protocol (RSVP) provides for the routers to reserve the required
bandwidth for the voice connections, and Real-time Transport Protocol (RTP) uses
synchronization.
Figure 8: The Voice architecture over MPLS / Diffserv domain
10. Challenges with VOIP
Voice is a real-time service. It must be delivered with minimal delay (150 milliseconds
end-to-end is a common recommendation) and it must be reproduced with a constant bit
stream on the egress network or endpoint. Due to the delay requirements, IP
retransmissions are not allowed. Therefore, packets that are dropped on the network, or
late packets dropped by a jitter buffer, are not saved or reproduced. IP’s best effort
delivery and non-deterministic routing introduce delay and more importantly variance in
delay, also known as packet jitter, in the voice transmission. VOIP packets may be lost
due to packets dropped in router queues or by the jitter buffer.
Conclusion
MPLS enables service providers to deliver new services governed by specific SLAs and
COS. These services comprise the triple play: offering real-time voice and video along
with data on a common network. It is the real-time services like voice that will generate
the most revenue. The ability to keep these services running at quality levels that meet
customer expectations is crucial to retaining customers and realizing revenues. While
MPLS introduces new challenges to diagnosing and troubleshooting service-level
problems, advanced tools like the Agilest Network Analyzer makes this job simple and
fast for next generation network engineers and technicians.
These results suggest that an MPLS service is not the panacea for VoIP. MPLS service is
in fact essentially comparable to Internet service. Both provide good base connectivity,
but by themselves neither can deliver the quality and availability required for business-
quality voice communication.
To discover how can reduce the impact of bad minutes on VOIP communication over
both MPLS and Internet links, please refer to Performance of Virtualized MPLS Internet
Infrastructure in Delivering VOIP Service.