• Skip to main content
  • Skip to footer

NetworkJutsu

Networking & Security Services | San Francisco Bay Area

  • Blog
  • Services
  • Testimonials
  • About
    • About Us
    • Terms of Use
    • Privacy Policy
  • Contact Us

Blog

QoS Requirements and Recommendations for Voice (Bearer Traffic)

10/31/2011 By Andrew Roderos Leave a Comment

Key QoS requirements and recommendations for voice (bearer traffic):

  • Voice traffic should be marked to DSCP EF per the QoS Baseline and RFC 3246.
  • Loss should be no more  than 1 percent.
  • One-way latency (mouth to ear) should be no more than 150 ms.
  • Average one-way jitter should be targeted at less than 30 ms.
  • A range of 21 to 320 Kbps of guaranteed priority bandwidth is required per call (depending on the sampling rate, the VoIP codec, and Layer 2 media overhead).

Reference

End-To-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Filed Under: QoS Tagged With: Cisco, IOS

Main Components of MQC

10/30/2011 By Andrew Roderos Leave a Comment

There are three main components that make up the MQC (Modular QoS CLI) and are listed below:

  • class-map – This is used as a classification filter defined within the policy map to identify traffic for preferential or deferential treatment. Traffic can be identified by IPP or DSCP, named or numbered ACL, Network-Based Application Recognition (NBAR), Layer 2 parameters (CoS, FR DE, ATM cell loss priority [CLP], MPLS Experimental [EXP] value), or combination of all of these.
  • policy-map – This is used as a statement that defines how each traffic type, as identified by the class map(s), should be serviced. Options include marking/re-marking, policing, shaping, low-latency or class-based weighted fair queuing, selective dropping, and header compression.
  • service-policy – This is used as a statement that binds the policy to an interface and specifies direction

For example:

ip access-list extended VOICE-RTP
 permit udp 192.168.1.0 0.0.0.255 any range 16384 32767
ip access-list extended VOICE-SIGNALING
 permit tcp 192.168.1.0 0.0.0.255 any range 2000 2002
!
class-map match-all VOICE-SIGNALING
 match access-group name VOICE-SIGNALING
class-map match-all VOICE-RTP
 match access-group name VOICE-RTP
!
policy-map VOICE
 class VOICE-RTP
 set dscp ef
 class VOICE-SIGNALING
 set dscp cs3
!
interface Vlan10
 description Voice VLAN
 service-policy input VOICE
!
end

References

Cisco QoS Exam Certification Guide (IP Telephony Self-Study) (2nd Edition)
End-to-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Filed Under: QoS Tagged With: Cisco, IOS

Cisco QoS Toolset

10/29/2011 By Andrew Roderos Leave a Comment

Cisco QoS tools fall into these categories:

  • Classification and marking tools
  • Policing and shaping tools
  • Congestion-avoidance (selective dropping) tools
  • Congestion-management (queuing) tools
  • Link-specific tools

Click here for more information.

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Filed Under: QoS Tagged With: Cisco, IOS

PHB (Per-Hop Behavior)

10/28/2011 By Andrew Roderos Leave a Comment

According to End-To-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs book, there are four available standard PHBs (Per-Hop Behavior) and are listed below:

  • Expedited Forwarding (EF) – Provides a strict-priority service. This is similar to the Express Mail service of USPS.
  • Assured Forwarding (AF) – Provides a qualified delivery guaranteee and makes the provision for oversubscription to this service (specifically, markdown and dropping schemes for excess traffic). This is similar to Registered Mail service of USPS.
  • Class Selectors (CS) – Provides code points that can be used for backward compatibility with IP Precedence models.
  • Default PHB (Best-Effort Service) – Provides a “delivery when possible” or best effort service. This is similar to Regular Mail service of USPS.

Click here for more information.

Reference

End-To-End QoS Network Design: Quality of Service in LANs, WANs, and VPNs

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Filed Under: QoS Tagged With: Cisco, IOS

Layer 3 Link Load Balancing

10/27/2011 By Andrew Roderos Leave a Comment

CCDP ARCH book states to avoid CEF (Cisco Express Forwarding) polarization, the recommended way to do is to use alternating input hashes in the core and distribution layer. In the core, use the default hash, which is based on only Layer 3 information. In the distribution layer, use Layer 3 and 4 information as the input into the CEF hash algorithm.

To enable Layer 3 and 4 CEF hashing algorithm, issue this command:

Switch (config)# mls ip cef load-sharing full

Disclosure

NetworkJutsu.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.

Filed Under: Design Tagged With: Cisco, IOS

  • « Go to Previous Page
  • Go to page 1
  • Interim pages omitted …
  • Go to page 14
  • Go to page 15
  • Go to page 16
  • Go to page 17
  • Go to page 18
  • Go to Next Page »

Footer

WORK WITH US

Schedule a free consultation now!

LET’S TALK

Copyright © 2011–2023 · NetworkJutsu · All Rights Reserved · Privacy Policy · Terms of Use