Readying Data Networks for Converged Services

Presented by:Jaye Armstrong-CCIE

Director of Data Services

Readying Data Networks for Converged Services

• Introduction• Assessing and Qualities that effect

Converged Networks• Network Tools that effect

Converged Networks• Example Network

What is a Converged Network?Communications

• A converged network is a network that handles two or more different applications such as Data, Voice, and Video.

Convergence Requirements

• Any Successful Converged Solution starts with a • Complete assessment of the current network for:

• Speed and Duplex Settings of Devices• Current network applications and their priorities• Current Network devices and software revisions• Future Projects

Major Areas of Influence to Successful Deployment

• Every network should be mapped in detail and thoroughly assessed for the following factors:

• Duplex Settings• Bandwidth• Delay• Jitter• Loss

Duplex Settings

• Duplex is the ability to converse in both directions at the same time.

• All Telephone and Server equipment should be manually set to Full-duplex on the device and switch.

• All switch ports that will have different devices plugged in should be left to auto negotiate.

Bandwidth• Bandwidth is the number of bits per second that

can be transmitted across a medium.

• Point to Point links use the physical medium speed or clock rate of the interface to determine bandwidth.

• Frame-Relay links should use the CIR (Committed Information Rate) of the link.

Delay• Delay is experienced on every network from the time the

packet Is first sent and when it arrives at it’s destination.

• Serialization Delay• Propagation Delay• Forwarding/processing delay• Queuing Delay• Shaping Delay• Network Delay• Codec Delay• Compression Delay

Jitter• Jitter is the variation in the arrival rate of packets

that were sent in a uniform manner.

• Jitter is unavoidable but we can keep it to a point where it does not impact the quality of the service.

• Jitter is in a direct relationship with Bandwidth and Delay

Loss

• Packet loss can happen for many reasons but is not a concern in most modern networks.

Industry Standards for Delay, Loss, and Jitter

• Packet Loss - 1% or less can yield toll quality- 3% or less can provide Business

communication quality- greater than 3% may be

acceptable for voice

• Jitter - 20ms or less for Toll Quality• Delay - 80ms or less for Toll Quality• - 180ms or less for Business Quality

Network Tools that effect Converged Networks

• QoS – Quality of Service Tools• COS – Class of Service Marking• Queuing • Traffic Shaping• Fragmentation

Classification and Marking Tools• COS – Class of Service is the marking and classifying of

packets.

• Class of Service marking does no good if the devices are not configured to handle the marked traffic.

• True CoS uses the CoS field of an 802.1p/Q packet or the Layer 3 DSCP value in the packet.

• Other means of marking traffic is through Port numbers, IP addresses, etc through configuring access lists to identify the traffic.

Quality of Service Tools

• QoS – Quality of Service refers to the network devices actually

• Giving the tagged traffic different service levels.

• QoS on Layer 2 - queuing

• QoS on Layer 3 – queuing, traffic shaping, fragmentation

Bandwidth Tools

• Compression– Header Compression– Silence Suppression

• Codec Selection– G729 – Most Compression loss in quality– G711 – No Compression Best Quality

Example Network Topology

Voice 172.16.51.0 / 24 Data 172.16.52.0 / 24Data 172.16.54.0 / 24

Data 172.16.56.0 / 24Voice 172.16.53.0 / 24

Voice 172.16.55.0 /24

Avaya 8300Avaya 8300

Avaya 8300

DATA VLAN 1 (Existing) Main Voice VLAN 172.16.50.0/24

AVAYA 8700

IP PhonesIP Phones

IP Phones

Data Servers and PCsData Servers and PCs

Data Servers and PCs

Data Servers and PCs

Campus Remote SiteT1 Connected Remote Site

Frame Relay Connected Remote Site

HQ

Frame Relay

Example Campus Site

Voice 172.16.51.0 / 24 Data 172.16.52.0 / 24

Avaya 8300

DATA VLAN 1 (Existing) Main Voice VLAN 172.16.50.0/24

AVAYA 8700

IP Phones

Data Servers and PCs

Data Servers and PCs

Campus Remote Site

HQ

CoS Set on the Avaya 8700

Set switch to trust CoS from the8700 and enable queues forpriority.

CoS Set on the Avaya 8300 andIP Phones

Set switch to trust CoS from the8700 and enable queues forpriority.

This switch is also a router.The QoS values will have to bemapped to DSCP values forLayer 3 forwarding.

Example T1 Site

Data 172.16.54.0 / 24Voice 172.16.53.0 / 24

Avaya 8300

DATA VLAN 1 (Existing) Main Voice VLAN 172.16.50.0/24

AVAYA 8700

IP Phones

Data Servers and PCs

Data Servers and PCs

T1 Connected Remote Site

HQ

CoS Set on theAvaya 8300 and

IP Phones

CoS Set on theAvaya 8700

Set switch to trust CoS from the8700 and enable queues forpriority.

Set switch to trust CoS from the8300 and IP Phones and enable

queues for priority.

Set Routers to map CoS valuesto DSCP Values for Layer 3Forwarding

The VoIP Path will probably useg729 codec to enable more

calls across T1 Line

Steps to Success

• Planning– Make Sure all requirements are documented– Document Current Network – Review requirements

• Assess Network Before and After Configuration – Use a good assessment tool that injects Voice Traffic– Add QoS to network one step at a time and test!– Test Every possible scenario before putting into

production

THANK YOU

• For Further Questions:

• Jaye Armstrong• Lantana Communications• Director of Data Services• 817-606-3317• jarmstrong@lantanacom.com