advanced radio over ip

Presenta(on: Advanced radio over IP Speaker: Les Sco6

@CommsConnectAus #comms2014 COMMS CONNECT 2014

Agenda •  History, why RoIP ma6ers in our industry •  The difference between RoIP & VoIP

–  how radio systems differ from phone systems. •  RoIP Evolu(on •  RoIP Design elements & making it work.

–  IP Networks; bandwidth; data vs voice; private vs public; quality; protocols; standards; configura(on & analysis tools; hardware; redundancy; security.

•  RoIP Open Standards –  APCO P25 -‐ CSSI, DFSI, ISSI; DMR – AIS; BSI –  Benefits –  Examples

•  Ques(ons?

CommsConnect 2014 2 © 2014 Zetron

Defini(on

•  RoIP – Radio over Internet Protocol – Voice digi(sed by Codec or Vocoder so it can be encapsulated in an IP data packet for transport across an IP LAN/WAN/the Internet

– Metadata (AKA Signalling) such as: Press To Talk, Carrier Detect, Caller ID, Status, Short Data Message.


History & Why RoIP Ma6ers •  Early systems connected via RF control, landlines or microwave

–  Circuit switched methods. –  Early internet was a slow dial-‐up service for most people

•  Faster commonly available IP LAN/WAN networks allowed radio & console systems to connect using emerging RoIP technology.

•  Digital radio & console systems evolved with enhanced na(ve RoIP connec(vity adding advanced metadata func(onality.

•  Tradi(onal Telco land line services are no longer available in favour of IP services in many countries – like Australia.

•  IP networks, services & equipment are ubiquitous, fast, low cost & the way of the future, which is why RoIP ma6ers in our industry.


Difference between VoIP & RoIP •  VoIP used with telephony systems & applica(ons

–  Defined set of func(ons (CLI, CND, Hold, transfer etc.) –  DTMF is the only in band signalling –  Full duplex, No PTT –  Predominantly standards based -‐ SIP (IETF RFC 3261) or ITU-‐T H.323


Difference between VoIP & RoIP •  RoIP used with two way radio systems

–  Varied set of func(ons (Manufacturer & radio technology dependant)

–  Half or full duplex –  Varied mul(ple in band signalling (DTMF, Selcall, MDC, TRC, CTCSS…)

–  PTT (mul(ple one to one or many sessions on ad-‐hoc basis, call set up (me is cri(cal)

–  Both standards based & proprietary methods •  Console systems connect to both radio & telephone systems

–  Today’s focus is on radio & console systems with na(ve (in-‐built) RoIP


RoIP Evolu(on •  Early days “box” at each end conver(ng 4WE&M circuit

voice to IP packets & back. A Voice codec such as 64kbps G.711 commonly used. –  OK for voice transport but not so friendly for tradi(onal in-‐band “signalling” such as Selcall/ANI systems

–  Lower bit rate codecs can totally destroy in-‐band signalling –  Various methods for sending metadata separately as serial data emerged

•  Box at each end was updated to server at the control end, box at the radio end –  This reduced the footprint at the control end by replacing mul(ple boxes with a server

–  Signalling conversion done in the smart remote box


RoIP Evolu(on

•  Modern digital systems have “na(ve” RoIP interfaces – P25 CSSI/DFSI/ISSI; DMR AIS; TETRA; others – Voice codecs/vocoders are op(mised for intelligibility & data efficiency (low bit rate)

– Send enhanced metadata as data packets


Design Topics & Making it Work •  RoIP Network

–  Bandwidth – Data vs Voice –  Private vs Public – Quality –  Protocols –  Standards –  Configura(on & analysis tools – Hardware –  Redundancy –  Security


RoIP Network •  A Mission-‐cri(cal voice system must be reliable. •  A network suitable for data might not be suitable for Voice. – Most networks were originally designed for data not voice.

•  Nobody no(ces if DATA packets are lost, data can wait & do retries.

•  Lost VOICE packets are no(ced instantly as lost words or syllables –  Shoot or don’t shoot?

•  Without network management, data applica(ons can hog all available bandwidth in a WAN.


Bandwidth -‐ Data & Voice

A. Typical Voice Application Payload (Predictable)

B. Typical Data Application Payload (Unpredictable)

C. Combined Unpredictable Payload

Maximum Fixed

Bandwidth

Maximum Fixed Bandwidth

Delayed Data Packets & LOST Voice Packets


Public Network

Unpredictable Bandwidth

Typical Voice Application Payload

Bandwidth reduced by traffic of public users

Theoretical max Bandwidth LOST Voice Packets

•  The easiest of all configura(ons to reliably support mission-‐cri(cal RoIP is a private, dedicated (non-‐shared) network.


Parameters Impac(ng RoIP Reliability

•  Low throughput •  Dropped packets •  Errors •  Latency •  Ji6er •  Out-‐of-‐order delivery


Priori(za(on & QoS

•  Priori(za(on improves voice delivery in a shared network. – Give priority to RoIP devices (HW port priority or IP address/port priority)

– Give priority to RoIP packets (Quality of Service – QOS)

– Priori(za(on generally doesn’t help on a public network.

– QOS is defined by IEEE P802.1p


QoS IEEE P802.1p

CommsConnect 2014 16

PCP Priority Acronym Traffic Types1 0 (lowest) BK Background0 1 BE Best Effort2 2 EE Excellent Effort3 3 CA Critical Applications4 4 VI Video, < 100 ms latency and jitter5 5 VO Voice, < 10 ms latency and jitter6 6 IC Internetwork Control7 7 (highest) NC Network Control

© 2014 Zetron

RoIP Data Efficiency

•  Low bit rate codec to convert voice to data – Voice over the radio air interface is BW constrained

•  UDP instead of TCP – Non-‐assured vs assured delivery for real-‐(me voice

•  Mul(cast instead of unicast – One to many with single IP stream


Firewalls

Routers

Switches

Hubs

TCP/IP Protocols

Layer 1

Layer 2

Layer 3

Layer 4


Firewalls

Routers

Switches

Hubs

TCP/IP HW


TCP vs UDP •  TCP Transmission Control Protocol

–  Supervised transport knows whether or not packet was received by the far end & allows for retries if not received.

– Generally used for non streaming data. •  UDP User Datagram Protocol

– Unsupervised transport does not know whether or not a packet was received by the far end.

– Used for streaming data (video, voice) where acknowledgements would otherwise increase the network traffic & result in delays


TCP vs UDP


TCP packet contains provisions for acknowledgement. 192 byte overhead/packet.

UDP packet contains no provision for acknowledgement. 64 byte overhead/packet.

© 2014 Zetron

RTP

•  Real Time Protocol –  IETF RFC3550

•  RTCP Real Time Control Protocol – Used to reconstruct out of order packets & detect losses

– Used to generate report sta(s(cs for connec(ons


Mul(cast & IGMP

•  Bandwidth efficient way to send voice from one source to many interested par(es – One to many with single IP packet stream

•  Network must be mul(cast aware •  Internet Group Management Protocol (IGMP)

– Requires configura(on on switch, router or other host

•  Radio & Console systems use Mul(cast IP


Mul(cast HW Issues •  IP Switches don’t care about the type of IP traffic passing through them

–  TCP, UDP, unicast or mul(cast –  Intelligent switches send only traffic des(ned for Ethernet address(s)

•  IP Routers & firewalls do care about the type of IP traffic passing through them.

–  Read packet contents to decide rou(ng –  Check for & allow or block by traffic type e.g UDP-‐IP or TCP-‐IP & port use

•  Consumer grade routers & firewalls will not pass bi-‐direc(onal mul(cast traffic.

•  Most residen(al ISPs will not allow you to send mul(cast to the internet. •  Commercial grade routers & firewalls can be configured to pass mul(cast

traffic. –  Some can tunnel mul(cast through a unicast-‐only network.

•  Mul(cast in a new dedicated single level network is simple. •  Mul(cast with routers and/or a shared network is more complex.


Standards

•  TCP, UDP, RTP & SIP are all standards developed by the Internet Engineering Task Force (IETF).

•  IETF standards are called RFCs (Request for comment).

•  There are no IETF RFCs for “RoIP”


RoIP Standards

•  Unless a vendors “RoIP” interface is made to a standard, it will be incompa(ble with other vendors RoIP systems

•  Examples of open Standard RoIP interfaces – TIA: CSSI; DFSI; ISSI – DMRA: AIS – BSI Bridging Systems Interface


P25 Open Standards

•  TIA developed & published APCO standards •  Standardiza(on Drivers/Benefits

–  Interoperability between systems – Compe((on between vendors – Enhanced features & func(ons – Spectral efficiency


DFSI Digital Fixed Sta7on Interface

CSSI Console Sub-‐System Interface

P25 Standards Mobiles

Portables

P25 Console Sub-‐System

P25 Console Operator

Conven4onal Repeaters

ISSI Inter RF Sub-System Interface

P25 Trunked RF Sub-‐System A

Trunked Repeaters

CAI Common Air Interface

P25 Trunked RF Sub-‐System B


P25 RoIP Func(ons

•  RoIP control & metadata provides func(ons –  Individual call, group call, emergency call – Caller ID, talk group ID – Radio check, call alert, status update, – Radio unit monitor, radio stun, radio revive – Mul(ple encryp(on func(ons.

•  Func(ons used by subscribers & consoles


RoIP Configura(on

•  P25 CSSI example – Lots more parameters to configure – Using GUI to Display meta-‐data in meaningful way – Analysis tools – Redundancy


Configura(on P25 CSSI •  CSSI configura(on parameters

–  One console system CSSI connec(on to each RFSS in the radio network

–  RFSS Applica(on IP address – WACN –  System ID –  RFSS ID –  TG ID range –  SUID range –  AnnGID’s –  SysGID –  Understanding fleet mapping is very important


Console GUI – TG & Call Stack


Console GUI TG Resource

CommsConnect 2014

GUI Icon

TG “Encrypted”

GUI Icon

“Announce GP”

33 © 2014 Zetron

GUI Icon Examples


Console GUI Call Stack •  Call stack displays P25 metadata –  Time –  Caller ID/Alias –  Status –  Call state –  Emergency


CSSI Getng Connected •  Configure Parameters

–  RFSS IP address, WACN, System ID, RFSS ID, TG ID range, SUID range, AnnGID, SysGID, etc.

•  Connec(vity check –  Ping RFSS, confirm network connec(vity

•  Check console func(ons –  Individual call, group call, emergency call, announce group call, system

call, radio check, status query, remote unit monitor, stun, revive etc. •  If it doesn’t work – use diagnos(cs tools to check CSSI-‐RFSS

messages –  SIP invite –  SIP op(ons –  RFSS capability –  Registra(ons


Tools -‐ Wireshark


Wireshark Packet Analysis SIP Op(ons


OPTIONS sip:TIA-‐P25-‐[email protected];user=TIA-‐P25-‐RFSS SIP/2.0 To: <sip:TIA-‐P25-‐[email protected];user=TIA-‐P25-‐RFSS> From: <sip:TIA-‐P25-‐[email protected];user=TIA-‐P25-‐RFSS>;tag=066741390402505 Via: SIP/2.0/UDP 01.4A0.BEE00.p25dr;branch=z9hG4bK780x2336e9aa7 Allow: ACK,BYE,CANCEL,INVITE,OPTIONS,REGISTER,MESSAGE Call-‐ID: [email protected] Accept: applica(on/sdp;level=1,applica(on/x-‐(a-‐p25-‐issi,applica(on/x-‐(a-‐p25-‐supdat,applica(on/x-‐(a-‐p25-‐issi-‐90 CSeq: 1 OPTIONS Max-‐Forwards: 70 Content-‐Length: 0

© 2014 Zetron

Wireshark Packet Analysis SIP Op(ons SIP/2.0 200 OK Via: SIP/2.0/UDP 01.4A0.BEE00.p25dr;received=10.70.2.1;branch=z9hG4bK780x2336e9aa7 Call-‐ID: [email protected] From: <sip:TIA-‐P25-‐[email protected];user=TIA-‐P25-‐RFSS>;tag=066741390402505 To: <sip:TIA-‐P25-‐[email protected];user=TIA-‐P25-‐RFSS> CSeq: 1 OPTIONS MIME-‐Version: 1.0 Allow: INVITE, ACK, BYE, CANCEL, REGISTER, MESSAGE, OPTIONS Accept: applica(on/sdp;level=1, applica(on/x-‐(a-‐p25-‐issi, applica(on/x-‐(a-‐p25-‐issi-‐18, applica(on/x-‐(a-‐p25-‐supdat Content-‐Disposi(on: session; handling=required Content-‐Type: applica(on/x-‐(a-‐p25-‐issi Content-‐Length: 236 r-‐us:1, r-‐uc:1, r-‐gs:1, r-‐gc:1, r-‐ecg:0, r-‐ccg:0, r-‐sd-‐ea:0, r-‐sd-‐ec:0, r-‐sd-‐gc:0, r-‐sd-‐ca:1, r-‐sd-‐sm:1, r-‐sd-‐sq:1, r-‐sd-‐su:0, r-‐sd-‐rm:1, r-‐sd-‐re:0, r-‐sd-‐rc:0, r-‐sd-‐rd:0, r-‐sd-‐ri:0, r-‐sd-‐ru:0, r-‐pd:0, r-‐ru:0, r-‐rg:0, r-‐rk:0


Wireshark Stream Analysis Console •  less than ideal sta(s(cs •  Maximum delta 65ms,

packets have been delayed in sender or network.

•  Larger maximum ji6er but small average ji6er indicates sender or network has variable delays.

•  High skew, clock on sender is not disciplined and has dri{ed rela(ve to receiver during the call.

•  But no lost or out-‐of-‐order packets, delivery is reliable.


Tools -‐ IP Stats AVC


Tools -‐ SNMP

•  Integra(on with standard IT management & repor(ng solu(ons

•  Alarms •  Usage sta(s(cs


Hardware

•  IP has changed the hardware landscape – COTS HW vs Embedded – Console is a PC (desktop, laptop, tablet) & media dock

– Ethernet Switches – Routers – Customer selected HW Match exis(ng service agreements or IT environment

– Spares freely available off the shelf CommsConnect 2014 43 © 2014 Zetron

COTS Server HW Example

CommsConnect 2014

Model Processor Memory Hard Drive Power Supply Warranty OS Cost

Dell R210 II

1x Xeon E2-‐1230v2, 3.3GHz, 4C/8T

4GB (2x2GB,) Non–redundant, ECC

1x 500GB 7200 RPM, Internal Non-‐redundant

1 Year, Next Business Day CentOS 6.4 $1,300

Dell R6202x Xeon E5-‐2630, 2.3GHz, 6C/12T

8GB (4x2GB), Non–redundant, ECC

2x 500GB 7200 RPM, RAID 1, Hot-‐plug

Platinum efficiency, Non-‐redundant



32GB (16x2GB), Redundant, ECC


Platinum efficiency, Redundant





Titanium efficiency, Redundant

7 Year, 2 hour response, Mission Critical CentOS 6.4 $12,550



2x 300GB Solid State, RAID 1, Hot-‐plug

Titanium efficiency, Redundant

7 Year, 2 hour response, Mission Critical

RHEL 6.4, 7 year subscription $24,050

44 © 2014 Zetron

Hardware IP Consoles

•  Console is a Windows PC •  Media Dock USB connec(on to PC – Headset, handset, footswitch, speakers connect to media dock


Hardware Base Sta(ons

•  Base Sta(ons & Repeaters have na(ve Ethernet connec(vity

•  Ethernet is used for: – Direct console connec(on via DFSI – Alarms and Monitoring over SNMP –  Configura(on & Remote Management

– NTP for (me synchronisa(on –  Connec(on to other base sta(ons for wide area networks


HW Redundancy

•  Geographic diversity console & radio systems •  H/A RFSS Server

–  Floa(ng IP address – Mul(ple address

•  Console system – Main/Standby or HA Servers

•  Console – Dual NIC PC, LAN A, LAN B – AVC monitors sta(s(cs on links


Security •  P25 AES/DES Encryp(on

–  Voice is encrypted –  KFD, KMF –  Storage of mul(ple keys, radios & consoles can auto detect & displaly clear vs

encrypted •  VLAN

–  Increases security by segrega(ng a shared physical network into isolated virtual networks.

•  IPSEC –  Allows secure tunnelling of traffic over third-‐party IP back-‐haul networks.

Open standard, available from many COTS routers. •  Firewall

–  Provides control over the network traffic that reaches cri(cal servers. Typically only the network ports & protocols that are required for the service provided are allowed through the firewall. Access to server management func(ons may be restricted to internal networks.

•  Physical access restric(ons


ROIP Voice Recorder Systems

•  Recorders interface with Radio Systems via IP •  Handle voice & meta data for mul(ple systems

– P25, DMR, SIP Telephony & Conven(onal interfaces

– Encryp(on & decryp(on, key loading, key store – Console Systems


Other System RoIP Interfaces

•  Other systems & applica(ons use the metadata elements of RoIP & require IP interfaces – CAD – AVL/GIS/Mapping

•  Consoles provide API for 3rd party systems


RoIP Conclusion

•  Radio over IP is important to our industry •  Allows rela(vely low cost system connec(vity •  Provides advanced features & func(ons •  Specialist skills needed to make it successful for mission cri(cal applica(ons

•  Open standards & COTS HW provide interoperability & compe((on

•  Thank you for a6ending •  Ques(ons?


www.comms-‐connect.com.au

Conference materials available soon at

COMMS CONNECT 2014 @CommsConnectAus #comms2014

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