[PPT] - Communication Network Logical connections PowerPoint Presentation

SLIDE 1

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✁

✂ ✄ ☎ ✆ ✂✞✝ ✟✠ ✝ ✡ ☛✌☞ ✂ ✡ ✟ ✂✞✝ ✟ ✍ ✎✑✏✒ ✓ ✏✔ ✏✕ ✖ ✏ ✗ ✏ ✕ ✘ ✙✚✛ ✜ ✢ ✣ ✙✤ ✢ ✥ ✦ ✧★ ✩✫✪ ✬ ✬✭✮ ✛ ✤ ✚ ✯ ✜

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✰ ✆✲✱ ✳ ✱ ✱ ✡ ✴✶✵ ☞

✁

✂ ✄ ☎ ✆ ✂ ✝ ✟ ✷ ✸ ✹ ✺ ✏ ✻ ✻✑✼ ✹ ✗✽ ✾ ✺ ✿✔ ✒ ✼ ✏ ✕ ✼ ✹ ✗ ✗ ✾ ✕ ❀ ✼ ✏ ✺ ✿ ❁ ❀ ✔ ✿ ✼ ✺ ✻✌❂ ❃ ❄ ❅❇❆ ❈ ❉ ❊❋

❉

❍ ❉ ■ ❋ ■ ❉ ❏❑ ❈ ❃ ▲ ■ ❅❇▼ ❍ ❋ ◆ ❖P◗ ❘ ❅ ❏ ❈ ■ ❈ ❃ ▲ ■ ❅❇▼ ❍ ❋ ◆ ◗ ❙ P P ❍ ✷ ❚❇❯ ❀ ✺ ✼ ✎✌❱ ❯ ✎ ✿ ✔ ✿ ✗ ✿ ✒ ✒ ✏❲ ✿ ✒ ✏ ✔ ✿ ✒ ❯ ❀ ✺ ✼ ✎ ✿ ❁❳ ❨ ✔ ✹ ✗ ✹ ✕ ✿ ❀ ✕ ✺ ✿ ✔ ❨ ✏ ✼ ✿ ✺ ✹ ✏ ✕ ✹ ✺ ✎ ✿ ✔ ❩

Communication Network

Logical connections

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✰❭❬ ❪ ✱ ❫ ✵ ✴

✁

✂ ✄ ☎ ✆ ✂ ✝ ✟

Packet Switching Source Routing Circuit Switching

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❴ ✠ ☎ ❵ ✱ ✄

✁

✂ ✄ ☎ ✆ ✂✞✝ ✟

Each packet carries destination information Switch

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

❛ ❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜

SLIDE 2

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✂

☞ ☎ ✁ ✂ ✄

✁

✂ ✄ ☎ ✆ ✂ ✝ ✟

There is a “circuit” from source to destination Switch

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✂

☞ ☎ ✁ ✂ ✄

✁

✂ ✄ ☎ ✆ ✂✞✝ ✟ ✂ ☎ ✵ ✝ ✄ ✂ ✝ ✁ ✱ ✡ ✄

Switch

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

☎ ✂ ☞ ✄ ✁ ✠ ✆

✂

☞ ☎ ✁ ✂ ✄

✁

✂ ✄ ☎ ✆ ✂ ✝ ✟

Switch

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

2 1 1 1 2 3 4 3 4 Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❴ ✠ ☎ ❵ ✱ ✄

✁

✂ ✄ ☎ ✆ ✂✞✝ ✟ ✂ ✝ ✠ ✳ ✱ ✄ ✁ ✵ ☞ ❵

0x4444 0x1111

Switch 100 Switch 200 Switch 400 Switch 300 Switch 500

Routing: how to route from source to destination?

❛ ❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜

SLIDE 3

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005 Switch 100 Switch 200 Switch 400 Switch 300 Switch 500

✂

☞ ☎ ✁ ✂ ✄

✁

✂ ✄ ☎ ✆ ✂ ✝ ✟ ✂ ✝ ✠ ✳ ✱ ✄ ✁ ✵ ☞ ❵

1 0x4444 0x1111

3 7 2

A circuit has to be setup before packets can be transferred

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005 Switch 100 Switch 200 Switch 400 Switch 300 Switch 500

✵

✁ ☞ ☎ ✱

✵

✁ ✄ ✂ ✝ ✟

100 200 400 0x4444

0x4444 0x1111

Similar to packet switching, but source decides the route

200 400 0x4444 400 0x4444 0x4444 Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✵

✁ ✱ ✂☎✄ ✠ ✁ ❪ ✆ ✱ ❫

Ethernet Internet Postal system

Packet Switching Circuit Switching

Telephone network

Asynchronous Transfer Mode (ATM)

Source Routing

Internet Protocol (IP) has this as an option

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✂ ✄ ✆✲✱ ☞ ✝ ✱ ✄ ☛ ☞ ✂ ✡ ✟ ✂ ✝ ✟

Bridge

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

Interface-1 Interface-2

An ethernet bridge with multiple interfaces acts as switch

❛ ❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜

SLIDE 4

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✵

☞ ✁ ✠ ☞ ✡ ✂ ✝ ✟ ✰ ✠ ✁ ✆ ✱ ✠ ✄ ✄ ✆✲✱ ☛ ☞ ✂ ✡ ✟ ✱

Bridge

0x4444 0x5555 0x6666 0x1111 0x2222 0x3333

Iface-1 Iface-2

Address Iface 0x1111 1 0x2222 1 0x3333 1 0x4444 2 0x5555 2 0x6666 2

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✂ ✱ ✠ ☞ ✝ ✂ ✝ ✟ ✄ ✆ ✱

✵

☞ ✁ ✠ ☞ ✡ ✂✞✝ ✟ ✰ ✠ ✁ ✆ ✱ ✷ ✄ ✏ ✕ ✾ ✏ ✻✑✼ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕ ☎ ☎ ✆ ✼ ✾ ✗ ✝ ✿ ✔ ✒ ✹ ✗ ✿ ✷ ✞ ✿ ✏ ✔ ✕ ❀ ✕ ❲ ❱ ❃ ✟ ❑ ❈✠ ✠ ❉ ❑ ✡ ❋ ☛✌☞ ❋ ❍ ✠ ✍ ❉ ■ ❅ ❋ ✎ ❋ ☞ ■ ❉ ❊ ✏

❋

☞ ❈❏ ✏ ☞ ❊ ✠ ❋ ✑ ✑ ☞ ✠ ❈ ❈ ❏❑ ❋ ❑ ❉ ❑ ■ ✠ ☞ ☛ ❋ ❊ ✠✓✒ ❍ ❋ ✔ ✠ ❋ ❑ ✠ ❑ ■ ☞ ❆ ❃ ✕ ☛ ❑ ❏ ✠ ❑ ■ ☞ ❆ ✠ ◆ ❉ ❈ ■ ❈ ☛ ❏ ☞ ❋ ✑ ✠ ❈ ■ ❉ ❑ ❋ ■ ❉ ❏❑ ✒ ✖ ☞ ❏ ❋ ✑ ❊ ❋ ❈ ■ ❏❑ ❋

❉

❑ ■ ✠ ☞ ☛ ❋ ❊ ✠ ❈ ❏ ■ ❅ ✠ ☞ ■ ❅ ❋ ❑ ■ ❅ ✠ ☞ ✠ ❊ ✠ ❉ ✗ ❉ ❑ ✡ ❉ ❑ ■ ✠ ☞ ☛ ❋ ❊ ✠

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❴ ☞ ✵ ✁ ✆ ✱ ✁ ✘ ☛ ☞ ✂ ✡ ✟ ✂ ✝ ✟ ✂ ✵ ✵ ❪ ❫ ✷ ✙ ✎ ❂ ✗ ❀ ❲ ✎ ✺ ✺ ✎ ❀ ✒ ✎ ✏ ✽ ✽ ✿ ✕ ✚ ❃ ✛ ❏❑ ☛ ❉ ✡ ✏ ☞ ❋ ■ ❉ ❏ ❑ ✠ ☞ ☞ ❏ ☞ ❃ ✟ ❑ ✎ ✏ ☞ ✎ ❏ ❈ ✠ ▼ ☛ ❋ ✏

■✢✜

■ ❏

✠

☞ ❋ ❑ ❊ ✠ ✷ ✣ ✔ ✹ ✝ ✻ ✿ ✗ ❱ ✻ ✹ ✹ ✽ ✒ ❀ ✕ ❨ ✹ ✔ ❯ ✏ ✔ ❁ ❀ ✕ ❲ ✷ ❚ ✹ ✻ ✾ ✺ ❀ ✹ ✕ ❱ ✒ ✽ ✏ ✕ ✕ ❀ ✕ ❲ ✤ ✺ ✔ ✿ ✿

B2 B3 B1

0x1111 0x2222

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❪

✠ ✝ ✝ ✂ ✝ ✟ ✰ ☞ ✱ ✱ ✂✞✝ ✄ ✆ ✱ ☛✌☞ ✂ ✡ ✟ ✱ ✡ ✳ ✱ ✄ ✁ ✵ ☞ ❵ ✷ ✥ ✿ ❨ ❀ ✕ ✿ ✏ ❲ ✔ ✏ ✽ ✎ ❃ ✛ ❏ ❑ ❈ ❉ ✑ ✠ ☞ ✠ ❋ ❊ ❅ ✖ ☞ ❉ ✑ ✡ ✠ ❋ ❑ ✑ ✠ ❋ ❊ ❅ ✦ ✧★ ✜ ❈ ✠ ✡ ❍ ✠ ❑ ■ ❋ ❈ ❋ ❑ ❏ ✑ ✠ ❃ ✧ ❑ ✑ ✠ ❋ ❊ ❅ ❉ ❑ ■ ✠ ☞ ☛ ❋ ❊ ✠ ✩ ✎❏ ☞ ■ ❋ ❈ ❋

❉

❑ ✔ ✷ ✪ ✒ ✽ ✏ ✕ ✕ ❀ ✕ ❲ ✺ ✔ ✿ ✿ ❀ ✕ ✺ ✎ ❀ ✒ ❲ ✔ ✏ ✽ ✎ ❀ ✒ ❁ ✿ ❨ ❀ ✕ ✿ ❁ ✷ ✙ ✎ ❀ ✼ ✎ ✒ ✽ ✏ ✕ ✕ ❀ ✕ ❲ ✺ ✔ ✿ ✿ ✚

A graph A spanning tree

f the graph

❛ ❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜

SLIDE 5

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✱

✴ ✂ ✝ ✂ ✝ ✟ ✄ ✆ ✱

❪

✠ ✝ ✝ ✂ ✝ ✟ ✰ ☞ ✱ ✱ ✷ ✁ ✏ ✼ ✎ ✝ ✔ ❀ ❁ ❲ ✿ ✎ ✏ ✒ ✺ ✹ ✒ ✿ ✻ ✿ ✼ ✺ ❀ ✺ ✒ ✏ ✼ ✺ ❀ ✂ ✿ ❀ ✕ ✺ ✿ ✔ ❨ ✏ ✼ ✿ ✒ ✷ ✥ ✿ ❨ ❀ ✕ ✿ ✏ ✔ ✹ ✹ ✺ ✝ ✔ ❀ ❁ ❲ ✿ ❱ ✒ ✗ ✏ ✻ ✻ ✿ ✒ ✺ ❀ ❁ ❃ ✧

❏

☛ ❉ ■ ❈ ❉ ❑ ■ ✠ ☞ ☛ ❋ ❊ ✠ ❈ ❋ ☞ ✠ ❋ ❊ ■ ❉ ✗ ✠ ✷ ✁ ✏ ✼ ✎ ✝ ✔ ❀ ❁ ❲ ✿ ✼ ✹ ✗ ✽ ✾ ✺ ✿ ✒ ✺ ✎ ✿ ✒ ✎ ✹ ✔ ✺ ✿ ✒ ✺ ✽ ✏ ✺ ✎ ✺ ✹ ✺ ✎ ✿ ✔ ✹ ✹ ✺ ✝ ✔ ❀ ❁ ❲ ✿☎✄ ✏ ✕ ❁ ✕ ✹ ✺ ✿ ✒ ✺ ✎ ❀ ✒ ❀ ✕ ✺ ✿ ✔ ❨ ✏ ✼ ✿ ✷ ✆ ✕ ✏ ✞ ✪ ✸ ✒ ✿ ❲ ✗ ✿ ✕ ✺ ✄ ✏ ✝ ✔ ❀ ❁ ❲ ✿ ❀ ✒ ❁ ✿ ✒ ❀ ❲ ✕ ✏ ✺ ✿ ❁ ✺ ✹ ✝ ✿ ✔ ✿ ✒ ✽ ✹ ✕ ✒ ❀ ✝ ✻ ✿ ❨ ✹ ✔ ❨ ✹ ✔ ❯ ✏ ✔ ❁ ❀ ✕ ❲ ❨ ✔ ✏ ✗ ✿ ✒ ✺ ✹ ❯ ✏✔ ❁ ✺ ✎ ✿ ✔ ✹ ✹ ✺ ✝ ✔ ❀ ❁ ❲ ✿ ❃ ✛

❏

❈ ✠ ❈ ■ ■ ❏ ■ ❅ ✠ ☞ ❏ ❏ ■ ✒ ❈❍ ❋

✠

☞ ✜ ❉ ✑ ■ ❏ ✖ ☞ ✠❋ ✔ ■ ❉ ✠ ❈

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❪

✠ ✝ ✝ ✂✞✝ ✟ ✰ ☞ ✱ ✱ ✘ ✝ ✝ ✂ ✄ ✠ ✁ ❪ ✆ ✱

B4 B3 B1 B2

A B C D E F

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

❪

✠ ✝ ✝ ✂ ✝ ✟ ✰ ☞ ✱ ✱ ✝ ✆ ✟ ✵ ☞ ✂ ✄ ✆ ✁ ✷ ✥ ❂ ✕ ✏ ✗ ❀ ✼ ✄ ❁ ❀ ✒ ✺ ✔ ❀ ✝ ✾ ✺ ✿ ❁ ✏ ✻ ❲ ✹ ✔ ❀ ✺ ✎ ✗ ✷ ✁ ✏ ✼ ✎ ✝ ✔ ❀ ❁ ❲ ✿ ✒ ✺ ✏ ✔ ✺ ✒ ✝ ❂ ✺ ✎ ❀ ✕ ✓ ❀ ✕ ❲ ❀ ✺ ✒ ✿ ✻ ❨ ✺ ✹ ✝ ✿ ✺ ✎ ✿ ✔ ✹ ✹ ✺ ✷ ✞ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕ ✗ ✿ ✒ ✒ ✏❲ ✿ ✒ ✏ ✔ ✿ ✒ ✿ ✕ ✺ ❯ ❀ ✺ ✎ ❱ ✒ ✿ ✕ ❁ ❀ ✕ ❲ ✝ ✔ ❀ ❁ ❲ ✿ ✟ ✒ ❀ ❁ ❳ ✠ ❩ ✄ ❀ ❁ ✹ ❨ ✺ ✎ ✿ ✕ ✹ ❁ ✿ ❀ ✺ ✼ ✹ ✕ ✒ ❀ ❁ ✿ ✔ ✒ ✺ ✹ ✝ ✿ ✺ ✎ ✿ ✔ ✹ ✹ ✺ ❳ ✡ ❩ ✄ ✏ ✕ ❁ ✺ ✎ ✿ ❁ ❀ ✒ ✺ ✏✕ ✼ ✿ ❨ ✔ ✹ ✗ ✡ ❳ ❁ ❩ ✷ ☛ ✔ ✹ ✗ ✏ ✗ ✹ ✕ ❲ ✺ ✎ ✿ ✼ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕ ✗ ✿ ✒ ✒ ✏ ❲ ✿ ✒ ✒ ✿ ✕ ✺ ✏ ✕ ❁ ✔ ✿ ✼ ✿ ❀ ✂ ✿ ❁ ✄ ❀ ✺ ✒ ✺ ✹ ✔ ✿ ✒ ✺ ✎ ✿ ☞ ✝ ✿ ✒ ✺ ✌ ✼ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✆

✵ ✵ ❫ ✂ ✝ ✟ ✄ ✆✲✱ ✍ ☛ ✱ ❫ ✄ ✎

✵

✝ ✴ ✂ ✟ ✁ ☞ ✠ ✄ ✂ ✵ ✝ ✏ ✱ ❫ ❫ ✠ ✟ ✱ ✷ ✪ ✗ ✹ ✕ ❲ ✺ ❯ ✹ ✗ ✿ ✒ ✒ ✏ ❲ ✿ ✒ ✗ ✑ ✏ ✕ ❁ ✗ ✒ ❃ ✟ ❑ ✠ ✍ ❅ ❉ ❊ ❅ ❉ ✑ ✠ ❑ ■ ❉ ☛ ❉ ✠ ❈ ❋ ❈❍ ❋

✠

☞ ☞ ❏ ❏ ■ ❉ ✑ ❉ ❈ ✖ ✠ ■ ■ ✠ ☞ ✒ ❏ ☞ ❃ ✟ ❑ ✠ ✍ ❅ ❉ ❊ ❅ ❅ ❋ ❈ ❋ ❈ ❅ ❏ ☞ ■ ✠ ☞ ✑ ❉ ❈ ■ ❋ ❑ ❊ ✠ ■ ❏ ■ ❅ ✠ ☞ ❏ ❏ ■ ✒ ❏ ☞ ❃ ✟ ❑ ✠ ✍ ❅ ❉ ❊ ❅ ❅ ❋ ❈ ❋ ❈ ❍ ❋

✠

☞ ❈ ✠ ❑ ✑ ❉ ❑ ✡ ✖ ☞ ❉ ✑ ✡ ✠ ❉ ✑ ✷ ✓ ✕ ✼ ✿ ✏ ✝ ✔ ❀ ❁ ❲ ✿ ❀ ❁ ✿ ✕ ✺ ❀ ❨ ❀ ✿ ✒ ❀ ✺ ✒ ✿ ✻ ❨ ✺ ✹ ✝ ✿ ✕ ✹ ✺ ✺ ✎ ✿ ✔ ✹ ✹ ✺ ✄ ❀ ✺ ✒ ✺ ✹ ✽✒ ❲ ✿ ✕ ✿ ✔ ✏ ✺ ❀ ✕ ❲ ✼ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕ ✗ ✿ ✒ ✒ ✏❲ ✿ ✒ ✷ ✖ ✹ ✹ ✺ ✒ ✿ ✕ ❁ ✒ ✼ ✹ ✕ ❨ ❀ ❲ ✾ ✔ ✏ ✺ ❀ ✹ ✕ ✗ ✿ ✒ ✒ ✏❲ ✿ ✒ ✽ ✿ ✔ ❀ ✹ ❁ ❀ ✼ ✏ ✻ ✻✌❂ ❛ ❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜

SLIDE 6

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✂ ✂ ✁ ✂ ✄ ✠ ✄ ✂ ✵ ✝ ❫ ✵ ✴ ☛ ☞ ✂ ✡ ✟ ✂ ✝ ✟ ✷ ❚ ✽ ✏ ✕ ✕ ❀ ✕ ❲ ✺ ✔ ✿ ✿ ✏ ✻ ❲ ✹ ✔ ❀ ✺ ✎ ✗ ✒ ✼ ✏ ✻ ✿ ✒ ✻ ❀ ✕ ✿ ✏ ✔ ✻ ❂ ✷ ✍ ✔ ✹ ✏ ❁ ✼ ✏ ✒ ✺ ❨ ✔ ✏ ✗ ✿ ✒ ✏ ✔ ✿ ✒ ✿ ✕ ✺ ✿ ✂ ✿ ✔ ❂ ❯ ✎ ✿ ✔ ✿ ❃ ▲ ◆ ❋ ❍ ✎

✠

▼ ✧ ❄ ✒ ✁✂ ✛ ❄

Fundamentals of Wired and Wireless Networks, Kameswari Chebrolu and Bhaskaran Raman, 09-13 May 2005

✁

✁ ✁ ✠ ☞ ❬ ✷ ❚❇❯ ❀ ✺ ✼ ✎ ❀ ✕ ❲ ❱ ✽ ✏ ✼ ✓ ✿ ✺ ✄ ✼ ❀ ✔ ✼ ✾ ❀ ✺ ✄ ✒ ✹ ✾ ✔ ✼ ✿ ✔ ✹ ✾ ✺ ❀ ✕ ❲ ✷ ✁ ✺ ✎ ✿ ✔ ✕ ✿ ✺ ✝ ✔ ❀ ❁ ❲ ❀ ✕ ❲ ❃ ✦ ✠ ❋ ☞ ❑ ❉ ❑ ✡ ✖ ☞ ❉ ✑ ✡ ✠ ❈ ❃ ✄ ✎ ❋ ❑ ❑ ❉ ❑ ✡ ■ ☞ ✠ ✠ ✎ ☞ ❏ ■ ❏ ❊ ❏

❛

❜❝ ❞❡ ❝ ❡ ❛ ❛ ❜ ❞❢❇❣ ❤ ❜