Presenta(on: Advanced radio over IP Speaker: Les Sco6 @CommsConnectAus #comms2014 COMMS CONNECT 2014
May 10, 2015
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.
CommsConnect 2014 3 © 2014 Zetron
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.
CommsConnect 2014 4 © 2014 Zetron
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
CommsConnect 2014 5 © 2014 Zetron
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
CommsConnect 2014 6 © 2014 Zetron
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
CommsConnect 2014 7 © 2014 Zetron
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
CommsConnect 2014 8 © 2014 Zetron
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
CommsConnect 2014 9 © 2014 Zetron
Design Topics & Making it Work • RoIP Network
– Bandwidth – Data vs Voice – Private vs Public – Quality – Protocols – Standards – Configura(on & analysis tools – Hardware – Redundancy – Security
CommsConnect 2014 10 © 2014 Zetron
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.
CommsConnect 2014 11 © 2014 Zetron
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
CommsConnect 2014 12 © 2014 Zetron
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.
CommsConnect 2014 13 © 2014 Zetron
Parameters Impac(ng RoIP Reliability
• Low throughput • Dropped packets • Errors • Latency • Ji6er • Out-‐of-‐order delivery
CommsConnect 2014 14 © 2014 Zetron
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
CommsConnect 2014 15 © 2014 Zetron
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
CommsConnect 2014 17 © 2014 Zetron
Firewalls
Routers
Switches
Hubs
TCP/IP Protocols
Layer 1
Layer 2
Layer 3
Layer 4
CommsConnect 2014 18 © 2014 Zetron
Firewalls
Routers
Switches
Hubs
TCP/IP HW
CommsConnect 2014 19 © 2014 Zetron
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
CommsConnect 2014 20 © 2014 Zetron
TCP vs UDP
CommsConnect 2014 21
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
CommsConnect 2014 22 © 2014 Zetron
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
CommsConnect 2014 23 © 2014 Zetron
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.
CommsConnect 2014 24 © 2014 Zetron
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”
CommsConnect 2014 25 © 2014 Zetron
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
CommsConnect 2014 26 © 2014 Zetron
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
CommsConnect 2014 27 © 2014 Zetron
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
CommsConnect 2014 28 © 2014 Zetron
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
CommsConnect 2014 29 © 2014 Zetron
RoIP Configura(on
• P25 CSSI example – Lots more parameters to configure – Using GUI to Display meta-‐data in meaningful way – Analysis tools – Redundancy
CommsConnect 2014 30 © 2014 Zetron
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
CommsConnect 2014 31 © 2014 Zetron
Console GUI – TG & Call Stack
CommsConnect 2014 32 © 2014 Zetron
Console GUI TG Resource
CommsConnect 2014
GUI Icon
TG “Encrypted”
GUI Icon
“Announce GP”
33 © 2014 Zetron
GUI Icon Examples
CommsConnect 2014 34 © 2014 Zetron
Console GUI Call Stack • Call stack displays P25 metadata – Time – Caller ID/Alias – Status – Call state – Emergency
CommsConnect 2014 35 © 2014 Zetron
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
CommsConnect 2014 36 © 2014 Zetron
Tools -‐ Wireshark
CommsConnect 2014 37 © 2014 Zetron
Wireshark Packet Analysis SIP Op(ons
CommsConnect 2014 38
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
CommsConnect 2014 39 © 2014 Zetron
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.
CommsConnect 2014 40 © 2014 Zetron
Tools -‐ IP Stats AVC
CommsConnect 2014 41 © 2014 Zetron
Tools -‐ SNMP
• Integra(on with standard IT management & repor(ng solu(ons
• Alarms • Usage sta(s(cs
CommsConnect 2014 42 © 2014 Zetron
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
3 Year, Next Business Day CentOS 6.4 $2,000
Dell R6202x Xeon E5-‐2630, 2.3GHz, 6C/12T
32GB (16x2GB), Redundant, ECC
2x 500GB 7200 RPM, RAID 1, Hot-‐plug
Platinum efficiency, Redundant
3 Year, Next Business Day CentOS 6.4 $3,850
Dell R6202x Xeon E5-‐2630, 2.3GHz, 6C/12T
32GB (16x2GB), Redundant, ECC
2x 500GB 7200 RPM, RAID 1, Hot-‐plug
Titanium efficiency, Redundant
7 Year, 2 hour response, Mission Critical CentOS 6.4 $12,550
Dell R6202x Xeon E5-‐2630, 2.3GHz, 6C/12T
32GB (16x2GB), Redundant, ECC
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
CommsConnect 2014 45 © 2014 Zetron
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
CommsConnect 2014 46 © 2014 Zetron
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
CommsConnect 2014 47 © 2014 Zetron
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
CommsConnect 2014 48 © 2014 Zetron
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
CommsConnect 2014 49 © 2014 Zetron
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
CommsConnect 2014 50 © 2014 Zetron
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?
CommsConnect 2014 51 © 2014 Zetron
www.comms-‐connect.com.au
Conference materials available soon at
COMMS CONNECT 2014 @CommsConnectAus #comms2014