2tmaschool panel wind

7/29/2019 2tmaschool Panel Wind

1/12

WIND Network Development-Traffic&Performance Paola Gallazzi1

2nd TMA Phd School 6th June 2011 Napoli, ItalyBridging the gap between theory and practice in network monitoring and analysis

The role of traffic monitoring and analysisin Telecom Operators networks

From the ISP itc to the user:monitored QoS parameters on the WIND Internet&Data Network


2/12



1. Scope

2. Internet Performance AnalysisKPI analysis on the ISP interconnection links (carriers, NAPs and peerings links)

3. IP Network Performance AnalysisKPI analysis on BB&SBB, National and International links

4. IP monitoring using active probes

5. Broadband Fixed Internet QoSAgcom Deliberation 244/08/CSP project

Summary


3/12



1.Scope

Goal of this panel is to explain the role of Traffic Monitoring&Analysis in WIND Network.

On WIND Data&Internet Network a multitude of services is carried and its important to know the trend of themain defined quality indicators (KPI), not only to reach the placed objectives indicators (KPO) defined withEngineering Team, but also to identify and to suggest actions directed to optimize the performance and toallow Current Planning and Operation & Maintenance Team to plan necessary upgrades to avoid congestion

and worsening in performance.


4/12



2. Internet Performance Analysis

Interconnections to international carriers and peerings connections to national and international ISPs

realized through:the SDH transport layer with the Packet Over Sonet interfacesTen Gigabit Ethernet links, by international GWs

WIND POIs:

dedicated peering routersInternational gateways

Dedicated gateways for the interconnection to the main Italian NAPs (IXPs)


5/12



Role of traffic monitoring&analysis:

to monitor the state of congestion and the performances on the IP links toward the ISPs.

KPI worked out on three different levels of aggregation:a) traffic typology: national or international traffic

b) traffic direction: between Wind POPs and ISPsc) international carrier

Traffic Indicators :

Two thresholds on the utilization rate are then set, to point out the congestion level on the network:

Yellow Threshold (medium criticity): 70%


6/12



3. IP Network Performance Analysis Architectural levels in WIND IP Network:

Core: transit infrastructure built to interconnect PoPs one with each other and with Gateways.

PoP: interconnections of all the elements positioned on the national territory that must be served by IP

connectivity. PoP architectures come in many sizes and shapes as they can span big cities as well as

the small ones, and in many cases they can comprise a number of physical sites within the same logicalPoP.Edge: all network elements that have direct relations with clients and the final users of the IP network,i.e. WIND Customers belonging either to the Consumer or to the Corporate market. The Edges, being

part of the PoP, can be viewed as the most external part of the IP network.

Links classification:

WAN/LAN SuperBackbone links: links through the main transit routers, the international gw, thededicated national and international peering routers and legacy links between Level1 POP and

SuperBackbone (named BB group).WAN/LAN national links: interconnection from the dedicated peering router to the national ISPs, or

the dedicated GWs to the IXPs (named NAT group) .WAN/LAN international links: interconnection of the dedicated peering router to the internationalISPs/carriers (named INT group).


7/12



Role of traffic monitoring&analysis:

to monitor the state of congestion and the performances on the IP links.

Traffic and Performance Indicators :

Two thresholds on the utilization rate are then set, to point out the congestion level on the network:

Yellow Threshold (medium criticity): 70%


8/12



4. IP monitoring using active probesWIND is going to implement a network performance measurement tool that uses active probes to generate

traffic in a continuos, reliable and predictable manner between multiple nodes (onion like model) and acrossmultiple network paths, in order to calculate performance metrics, useful to understand the network qualitystatus for the different point to point network services and to better define KPO at different levels.

Network cover: from the edge to the external gateways

Paths definition: a matrix between the nodes on which different probes operation will be made. Probes configured in order to monitor per class traffic over the same path by the use of the DiffServ CodePoint (DSCP) bits in the header of the IP packets.

Queuing to prioritize the outgoing traffic on the probing interface implemented to minimize the influence, onthe results, of the measurement device itself.

Each active probe connected to the relevant routers and switches via different GigabitEthernet or ATM E3

interfaces.


9/12



Type of measurements worked out:

UDP Jitter Operation: response time, one-way delay, per direction jitter, per direction packet loss and

connectivity (detection and reporting of out of sequence and corrupted packets). It allows to obtain

precision information about network key transport parameters for mission critical and real time trafficapplications such as VoIP, video over IP, real time conferencing. The operation is made by generatingsynthetic UDP traffic from the active probe to a target router and by sending N UDP packets, each ofsize S, every T ms

ICMP Echo Operation: response time, jitter and connectivity. The ICMP Echo operation sends anICMP echo request packet and waits for the ICMP echo reply from the remote host.

DNS Operation: it measures the time needed to resolve a DNS query (either IP or host name) on aspecified name server.

Operation frequency, probing duration and packet size are defined for each measurement typology, for each

type of traffic and per node.


10/12



5. Broadband Fixed Internet QoSAgcom Deliberation 244/08/CSP project

The Agcom 244/08/CSP Deliberation, published on 21.01.09 as the update of the precedent deliberation131/06 CSP, regarding the monitoring on the quality of the Internet Fixed Access, has the double objectiveto have certified measures to compare the performance of the different providers, on the two most sold ADSL

broadband services, and to allow the final user to test, through a certified free sw downloadable from aspecified internet web site, the quality of his line. 2H2010 statistical values have been published at the URL:www.misurainternet.it

Monitoring architecture:

measurement clients location, where the twoPC/modem, one for each broadband service under

monitoring, are installed.The access network of the provider (MAN GbE)that collects the ADSL2+ test lines on the IPDSLAM

and gives the connectivity to the edge router on the

IP Network.The IP Network, from the BRAS/IPRA to the

dedicated gateways that allow the connectivity tothe IXPs LANs.

The IXPs where the measurements servers, both

for the statistical measures of the providers and for

the final users are installed.


11/12



Client location: Regional Inspectorate for all theproviders to obtain comparability of the performances of

the different providers.

Measurement location similar to the medium finaluser experience.

Clients active in Mestre, Firenze, Cagliari, Bari,

Palermo, Ancona and Torino.

Monitored Wind services:

LLU ADSL2+ flat 8MB download speed service(TuttoIncluso/Absolute)

LLU ADSL2+ PPU 1.2MB download speedservice (HappyNoLimit/ SuperHappyItaly)

The measurements are made between the client andthe server locations (IXPs): in this way tests run only on

the newtork of the single provider and the Internet hasno impact on the performances.


12/12



Monitored QoS parameters (ETSI EG 202 057-4):

Data transmission speed for FTP download and upload of test files (10xline profile). Metrics: 5-percentile, 95-percentile, mean value, standard deviation

Packet Delay (one way transmission time): half the time needed for an ICMP Echo Request/ReplyPacket (Ping Command). Metrics: mean value, 95-percentile & standard deviation

Packet loss ratio: ratio between the number of not replied ICMP Ping commands to the total numberof sent commands. Metrics: mean value

Unsuccessful data transmission ratio: ratio of unsuccessful data transmissions to the total number

of FTP transmission attempts. Metrics: mean value

FTP dw/up measure: 20 subsequent tests temporary decorrelated.

The files on the server have a dimension (D) related to the line profile speed (S).The transmission time T(ms) is therefore worked out as the time from the start of the FTP/put command to

the receiving of the transfer complete command.The time related to the connection to the server, login, binary mode set up is excluded from the measurement.

Data transmission speed (kbps) =D/T excluding from this measure the tests whose transmission timeis above Tmax, where Tmax=30xD/S

One way Packet Delay (ms): half of the time between the sending of an ICMP Echo Request message(packet 1024 byte) and the receiving of an ICMP Echo Reply message.

Measures (10 subsequent tests) are placed at intervals of 10 seconds one from each other to avoid

correlation.

2tmaschool panel wind

Documents