1. Wireless ISP Infrastructure
MikroTik
Director - John Tully
CTO – Arnis Riekstins
11 May, 2002
MikroTik

2. AP Platform multiple radios per AP
Increase aggregate bandwidth using non-overlapping frequencies
Re-use of network configurations such as firewalls and users
Network services closest to the user (PPPoE, DHCP, and PPTP)
11 May, 2002
MikroTik

3. From AP directly to client (no router on client site)
AP MAC registration table
Assign IP to MAC with ARP disabled
Restricted MAC level forwarding on wireless network
11 May, 2002
MikroTik

4. (cont) AP direct to client
PPPoE access concentrator
Overview
AC configuration demonstration
Window XP client configuration demonstration
Encryption – MPPE protocol, advantages in wireless
Radius authentication
no engineer needed for account changes
automatic billing with legacy systems
11 May, 2002
MikroTik

5. (cont) AP direct to client
Bandwidth setting
Tx and rx settings allow you to simulate DSL offers
Address assignment
11 May, 2002
MikroTik

6. (cont) AP direct to client
PPTP
DHCP assigns private IP address
PPTP on Windows
PPTP clients available back to Windows 3.11
Radius authentication
Scripting to set bandwidth (in v2.6)
Demonstration of setup, server and client
11 May, 2002
MikroTik

7. From Wireless Client Router to Client LAN
General description of client site router
Protects wireless network from hacking by customers
Offer services to customers
Masqueraded address
Static NAT for servers
11 May, 2002
MikroTik

8. From Wireless Client Router to Client LAN (cont)
Multiple client connected to same router
Per interface firewall
Multiple ethernet interfaces in client site router
Using a smart switch with router and VLAN tags on a port basis (v2.6)
Using an ethernet bridge and PPPoE or PPTP
11 May, 2002
MikroTik

9. From Wireless Client Router to Client LAN (cont)
MikroTik Packet Packer Protocol (M3P)
Wireless has high per packet overhead
Negotiating access to wireless medium
Acknowledgment and error correction
M3P packs small packets into a large wireless MAC packet and increase throughput up to four times (with 100 byte packets)
Automatically discovers other MikroTik routers with this feature enabled
11 May, 2002
MikroTik

10. From Wireless Client Router to Client LAN (cont)
Services to customers beyond an IP gateway
DHCP
Special firewall configurations
Per IP address accounting (even on masqueraded addresses)
Dedicated VPN tunnel between other offices
LAN bridge between other offices
11 May, 2002
MikroTik

11. From AP to the backbone Backup Links / Failover Increasing throughput
OSPF
Tunnels over non-OSPF networks to OSPF backbone networks
Increasing throughput
Aggregation of Interfaces multi-path routing
PPTP tunnel compression
11 May, 2002
MikroTik

12. From AP to the backbone (cont)
Types of backbone connections
additional point to point wireless 2.4GHz interfaces using non-overlapping frequency or 5.8GHz
licensed frequency microwave systems
DSL connection from Telco
Lease line from Telco using v.35 HDLC or E1/T1 interface in AP
Use of HomePNA 14Mb/s interface up to 1.3km with one twisted pair
Use of SDSL up to 2.3Mb/s and 5km (speed decreases with distance)
11 May, 2002
MikroTik

13. Bandwith shaping problems when there is no shaping
users get high speed local services on a "luck" basis
high paying users may get low quality service when bandwidth is not managed
backbones to wireless may get overloaded
basic description of queues and function
where to put queues
11 May, 2002
MikroTik

14. Bandwith shaping (cont)
simple queue and complex queue configuration
boss at client site wants better quality for himself
webserver and mail server may be specifically shaped based on usage
varied IP subnets may be put into one group with a certain allocation
11 May, 2002
MikroTik

15. Bandwith shaping (cont)
scripting may be used to change the bandwidth speed settings
for a day speed and night speed
tunnels linking enterprise networks may be shaped and charged according to speed
for example, a VPN tunnel with ethernet bridging between a company warehouse LAN and main office LAN
11 May, 2002
MikroTik

16. Bandwith shaping (cont)
DEMO CONFIGURATION AREA ON ROUTER FOR SHAPING
11 May, 2002
MikroTik

17. Interference and antenna co-location
2.4GHz frequencies (three non-overlapping)
omni versus sectoral
building top antenna co-location
plan with barriers between antenna that have an overlapping frequency
example, concrete structure such as elevator gear box houses
mount on sides of building one floor or more below roof top so that there is concrete separating the antennas
11 May, 2002
MikroTik

18. Interference and antenna co-location (cont)
2.4GHz frequencies (three non-overlapping)
omni versus sectoral
Reflections (plus and minus)
Signal may be reflected off another object to make a connection when there is no line of sight
Reflections may cause a direct signal to be cancelled
11 May, 2002
MikroTik

19. Interference and antenna co-location (cont)
Interference may be mistaken for cabling problems
Cable is too long (10m or less is suggested for client site – though locations close (less than 2km) to the AP may have very long cable
Water may have gotten into the strands of the cable (cable must be replaced)
11 May, 2002
MikroTik

20. Interference and antenna co-location (cont)
Grounding may be incorrect (if you see small sparks when connecting cables)
Radio cable may be located to some high voltage lines that can cause interference
11 May, 2002
MikroTik

21. Interference and antenna co-location (cont)
change polarity of overlapping frequency antennas for a 20dB drop
bandwidth test when installing antennas
small movements of the mount location may make giant differences
using antenna diversity
radio power and amplifiers
11 May, 2002
MikroTik

22. Sample system design Situation proposed by audience 11 May, 2002
MikroTik